MAX4051AEEE-T中文资料

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MAX483EESA+T中文资料

General DescriptionThe MAX481E, MAX483E, MAX485E, MAX487E–MAX491E, and MAX1487E are low-power transceivers for RS-485 and RS-422 communications in harsh environ-ments. Each driver output and receiver input is protected against ±15kV electro-static discharge (ESD) shocks,without latchup. These parts contain one driver and one receiver. The MAX483E, MAX487E, MAX488E, and MAX489E feature reduced slew-rate drivers that minimize EMI and reduce reflections caused by improperly termi-nated cables, thus allowing error-free data transmission up to 250kbps. The driver slew rates of the MAX481E,MAX485E, MAX490E, MAX491E, and MAX1487E are not limited, allowing them to transmit up to 2.5Mbps.These transceivers draw as little as 120µA supply cur-rent when unloaded or when fully loaded with disabled drivers (see Selector Guide ). Additionally, the MAX481E,MAX483E, and MAX487E have a low-current shutdown mode in which they consume only 0.5µA. All parts oper-ate from a single +5V supply.Drivers are short-circuit current limited, and are protected against excessive power dissipation by thermal shutdown circuitry that places their outputs into a high-impedance state. The receiver input has a fail-safe feature that guar-antees a logic-high output if the input is open circuit.The MAX487E and MAX1487E feature quarter-unit-load receiver input impedance, allowing up to 128 trans-ceivers on the bus. The MAX488E–MAX491E are designed for full-duplex communications, while the MAX481E, MAX483E, MAX485E, MAX487E, and MAX1487E are designed for half-duplex applications.For applications that are not ESD sensitive see the pin-and function-compatible MAX481, MAX483, MAX485,MAX487–MAX491, and MAX1487.ApplicationsLow-Power RS-485 Transceivers Low-Power RS-422 Transceivers Level TranslatorsTransceivers for EMI-Sensitive Applications Industrial-Control Local Area NetworksNext-Generation Device Features♦For Fault-Tolerant Applications:MAX3430: ±80V Fault-Protected, Fail-Safe, 1/4-Unit Load, +3.3V, RS-485 TransceiverMAX3080–MAX3089: Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited, RS-485/RS-422Transceivers ♦For Space-Constrained Applications:MAX3460–MAX3464: +5V, Fail-Safe, 20Mbps,Profibus, RS-485/RS-422 TransceiversMAX3362: +3.3V, High-Speed, RS-485/RS-422Transceiver in a SOT23 PackageMAX3280E–MAX3284E: ±15kV ESD-Protected,52Mbps, +3V to +5.5V, SOT23, RS-485/RS-422True Fail-Safe ReceiversMAX3030E–MAX3033E: ±15kV ESD-Protected,+3.3V, Quad RS-422 Transmitters ♦For Multiple Transceiver Applications:MAX3293/MAX3294/MAX3295: 20Mbps, +3.3V,SOT23, RS-485/RS-422 Transmitters ♦For Fail-Safe Applications:MAX3440E–MAX3444E: ±15kV ESD-Protected,±60V Fault-Protected, 10Mbps, Fail-Safe RS-485/J1708 Transceivers ♦For Low-Voltage Applications:MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E: +3.3V Powered, ±15kV ESD-Protected, 12Mbps, Slew-Rate-Limited, True RS-485/RS-422 TransceiversMAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E±15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers________________________________________________________________Maxim Integrated Products 1Ordering Information19-0410; Rev 4; 10/03For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .Ordering Information continued at end of data sheet.Selector Guide appears at end of data sheet .M A X 481E /M A X 483E /M A X 485E /M A X 487E –M A X 491E /M A X 1487E±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers2_______________________________________________________________________________________Supply Voltage (V CC ) (12V)Control Input Voltage (–R —E –, DE)...................-0.5V to (V CC + 0.5V)Driver Input Voltage (DI).............................-0.5V to (V CC + 0.5V)Driver Output Voltage (Y, Z; A, B)..........................-8V to +12.5V Receiver Input Voltage (A, B).................................-8V to +12.5V Receiver Output Voltage (RO)....................-0.5V to (V CC + 0.5V)Continuous Power Dissipation (T A = +70°C)8-Pin Plastic DIP (derate 9.09mW/°C above +70°C)....727mW14-Pin Plastic DIP (derate 10.00mW/°C above +70°C)..800mW 8-Pin SO (derate 5.88mW/°C above +70°C).................471mW 14-Pin SO (derate 8.33mW/°C above +70°C)...............667mW Operating Temperature RangesMAX4_ _C_ _/MAX1487EC_ A.............................0°C to +70°C MAX4__E_ _/MAX1487EE_ A...........................-40°C to +85°C Storage Temperature Range.............................-65°C to +160°C Lead Temperature (soldering, 10sec).............................+300°CDC ELECTRICAL CHARACTERISTICS(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.ABSOLUTE MAXIMUM RATINGSPARAMETERSYMBOL MINTYPMAX UNITS Driver Common-Mode Output VoltageV OC 3V Change in Magnitude of Driver Differential Output Voltage for Complementary Output States ∆V OD 0.2V Change in Magnitude of Driver Common-Mode Output Voltage for Complementary Output States ∆V OD 0.2V Input High Voltage V IH 2.0V Input Low Voltage V IL 0.8V Input CurrentI IN1±2µADifferential Driver Output (no load)V OD15V 2V Differential Driver Output (with load)V OD2 1.551.0-0.8mA0.25mA -0.2Receiver Differential Threshold Voltage-0.20.2V Receiver Input Hysteresis ∆V TH 70mV Receiver Output High Voltage V OH 3.5Receiver Output Low Voltage V OL 0.4V Three-State (high impedance)Output Current at ReceiverI OZR±1µA 12k ΩCONDITIONSDE = 0V;V CC = 0V or 5.25V,all devices except MAX487E/MAX1487E R = 27Ωor 50Ω, Figure 8R = 27Ωor 50Ω, Figure 8R = 27Ωor 50Ω, Figure 8DE, DI, –R —E–MAX487E/MAX1487E,DE = 0V, V CC = 0V or 5.25VDE, DI, –R —E–DE, DI, –R —E–-7V ≤V CM ≤12V V CM = 0VI O = -4mA, V ID = 200mV I O = 4mA, V ID = -200mV R = 50Ω(RS-422)0.4V ≤V O ≤2.4VR = 27Ω(RS-485), Figure 8-7V ≤V CM ≤12V, all devices except MAX487E/MAX1487EReceiver Input Resistance R IN-7V ≤V CM ≤12V, MAX487E/MAX1487E48k ΩV TH I IN2Input Current (A, B)V IN = 12V V IN = -7V V IN = 12V V IN = -7VVMAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 TransceiversSWITCHING CHARACTERISTICS—MAX481E/MAX485E, MAX490E/MAX491E, MAX1487EDC ELECTRICAL CHARACTERISTICS (continued)(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)M A X 481E /M A X 483E /M A X 485E /M A X 487E –M A X 491E /M A X 1487E±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers4_______________________________________________________________________________________SWITCHING CHARACTERISTICS—MAX483E, MAX487E/MAX488E/MAX489E(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)SWITCHING CHARACTERISTICS—MAX481E/MAX485E, MAX490E/MAX491E, MAX1487E(continued)(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)2251000Figures 11 and 13, C L = 100pF, S2 closed Figures 11 and 13, C L = 100pF, S1 closed Figures 9 and 15, C L = 15pF, S2 closed,A - B = 2VCONDITIONSns 45100t ZH(SHDN)Driver Enable from Shutdown toOutput High (MAX481E)nsFigures 9 and 15, C L = 15pF, S1 closed,B - A = 2Vt ZL(SHDN)Receiver Enable from Shutdownto Output Low (MAX481E)ns 45100t ZL(SHDN)Driver Enable from Shutdown toOutput Low (MAX481E)ns 2251000t ZH(SHDN)Receiver Enable from Shutdownto Output High (MAX481E)UNITS MINTYP MAX SYMBOLPARAMETERt PLH t SKEW Figures 10 and 12, R DIFF = 54Ω,C L1= C L2= 100pFt PHL Figures 10 and 12, R DIFF = 54Ω,C L1= C L2= 100pFDriver Input to Output Driver Output Skew to Output ns 20800ns ns 2000MAX483E/MAX487E, Figures 11 and 13,C L = 100pF, S2 closedt ZH(SHDN)Driver Enable from Shutdown to Output High2502000ns2500MAX483E/MAX487E, Figures 9 and 15,C L = 15pF, S1 closedt ZL(SHDN)Receiver Enable from Shutdown to Output Lowns 2500MAX483E/MAX487E, Figures 9 and 15,C L = 15pF, S2 closedt ZH(SHDN)Receiver Enable from Shutdown to Output Highns 2000MAX483E/MAX487E, Figures 11 and 13,C L = 100pF, S1 closedt ZL(SHDN)Driver Enable from Shutdown to Output Lowns 50200600MAX483E/MAX487E (Note 5)t SHDN Time to Shutdownt PHL t PLH , t PHL < 50% of data period Figures 9 and 15, C RL = 15pF, S2 closed Figures 9 and 15, C RL = 15pF, S1 closed Figures 9 and 15, C RL = 15pF, S2 closed Figures 9 and 15, C RL = 15pF, S1 closed Figures 11 and 13, C L = 15pF, S2 closed Figures 10 and 14, R DIFF = 54Ω,C L1= C L2= 100pFFigures 11 and 13, C L = 15pF, S1 closed Figures 11 and 13, C L = 100pF, S1 closed Figures 11 and 13, C L = 100pF, S2 closed CONDITIONSkbps 250f MAX 2508002000Maximum Data Rate ns 2550t HZ Receiver Disable Time from High ns 25080020002550t LZ Receiver Disable Time from Low ns 2550t ZH Receiver Enable to Output High ns 2550t ZL Receiver Enable to Output Low ns ns 1003003000t HZ t SKD Driver Disable Time from High I t PLH - t PHL I DifferentialReceiver SkewFigures 10 and 14, R DIFF = 54Ω,C L1= C L2= 100pFns 3003000t LZ Driver Disable Time from Low ns 2502000t ZL Driver Enable to Output Low ns Figures 10 and 12, R DIFF = 54Ω,C L1= C L2= 100pFns 2502000t R , t F 2502000Driver Rise or Fall Time ns t PLH Receiver Input to Output2502000t ZH Driver Enable to Output High UNITS MIN TYP MAX SYMBOL PARAMETERMAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers_______________________________________________________________________________________505101520253035404550OUTPUT CURRENT vs.RECEIVER OUTPUT LOW VOLTAGEM A X 481E -01OUTPUT LOW VOLTAGE (V)O U T P U T C U R R E N T (m A )1.52.02.51.00.50.10.20.30.40.50.60.70.80.9-60-2060RECEIVER OUTPUT LOW VOLTAGEvs. TEMPERATURETEMPERATURE (°C)O U T P U T L O W V O L T A G E (V )20100-4040800-5-10-15-20-251.53.0OUTPUT CURRENT vs.RECEIVER OUTPUT HIGH VOLTAGEM A X 481E -02OUTPUT HIGH VOLTAGE (V)O U T P U T C U R R E N T (m A )5.04.54.02.02.53.53.03.23.43.63.84.04.24.44.64.8-60-2060RECEIVER OUTPUT HIGH VOLTAGEvs. TEMPERATURETEMPERATURE (°C)O U T P U T H I G H V O L T A G E (V )20100-4040800102030405060708090DRIVER OUTPUT CURRENT vs. DIFFERENTIAL OUTPUT VOLTAGEM A X 481E -05DIFFERENTIAL OUTPUT VOLTAGE (V)O U T P U T C U R R E N T (m A )1.52.0 2.53.0 3.54.0 4.51.00.50__________________________________________Typical Operating Characteristics(V CC = 5V, T A = +25°C, unless otherwise noted.)NOTES FOR ELECTRICAL/SWITCHING CHARACTERISTICSNote 1:All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to deviceground unless otherwise specified.Note 2:All typical specifications are given for V CC = 5V and T A = +25°C.Note 3:Supply current specification is valid for loaded transmitters when DE = 0V.Note 4:Applies to peak current. See Typical Operating Characteristics.Note 5:The MAX481E/MAX483E/MAX487E are put into shutdown by bringing –R —E –high and DE low. If the inputs are in this state forless than 50ns, the parts are guaranteed not to enter shutdown. If the inputs are in this state for at least 600ns, the parts are guaranteed to have entered shutdown. See Low-Power Shutdown Mode section.M A X 481E /M A X 483E /M A X 485E /M A X 487E –M A X 491E /M A X 1487E±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers6___________________________________________________________________________________________________________________Typical Operating Characteristics (continued)(V CC = 5V, T A = +25°C, unless otherwise noted.)1.52.32.22.12.01.91.81.71.6-60-2060DRIVER DIFFERENTIAL OUTPUT VOLTAGE vs. TEMPERATURETEMPERATURE (°C)D I F FE R E N T I A L O U T P U T V O L T A G E (V )20100-404080020406080100120140OUTPUT CURRENT vs. DRIVER OUTPUT LOW VOLTAGEM A X 481E -07OUTPUT LOW VOLTAGE (V)O U T P U T C U R R E N T (m A )246810120-10-20-30-40-50-60-70-80-90-100-8-2OUTPUT CURRENT vs. DRIVER OUTPUT HIGH VOLTAGEM A X 481E -08OUTPUT HIGH VOLTAGE (V)O U T P U T C U R R E N T (m A )642-6-400100200300400500600-60-2060MAX481E/MAX485E/MAX490E/MAX491E SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (µA )20100-4040800100200300400500600-60-2060MAX483E/MAX487E–MAX489E SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (µA )20100-404080100200300400500600-60-2060MAX1487ESUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (µA )20100-404080±15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers_______________________________________________________________________________________7MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E______________________________________________________________Pin DescriptionM A X 481E /M A X 483E /M A X 485E /M A X 487E –M A X 491E /M A X 1487E±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers8_________________________________________________________________________________________________Function Tables (MAX481E/MAX483E/MAX485E/MAX487E/MAX1487E) Table 1. Transmitting__________Applications Information The MAX481E/MAX483E/MAX485E/MAX487E–MAX491E and MAX1487E are low-power transceivers for RS-485 and RS-422 communications. These “E” versions of the MAX481, MAX483, MAX485, MAX487–MAX491, and MAX1487 provide extra protection against ESD. The rugged MAX481E, MAX483E, MAX485E, MAX497E–MAX491E, and MAX1487E are intended for harsh envi-ronments where high-speed communication is important. These devices eliminate the need for transient suppres-sor diodes and the associated high capacitance loading. The standard (non-“E”) MAX481, MAX483, MAX485, MAX487–MAX491, and MAX1487 are recommended for applications where cost is critical.The MAX481E, MAX485E, MAX490E, MAX491E, and MAX1487E can transmit and receive at data rates up to 2.5Mbps, while the MAX483E, MAX487E, MAX488E, and MAX489E are specified for data rates up to 250kbps. The MAX488E–MAX491E are full-duplex transceivers, while the MAX481E, MAX483E, MAX487E, and MAX1487E are half-duplex. In addition, driver-enable (DE) and receiver-enable (RE) pins are included on the MAX481E, MAX483E, MAX485E, MAX487E, MAX489E, MAX491E, and MAX1487E. When disabled, the driver and receiver outputs are high impedance.±15kV ESD Protection As with all Maxim devices, ESD-protection structures are incorporated on all pins to protect against electro-static discharges encountered during handling and assembly. The driver outputs and receiver inputs have extra protection against static electricity. Maxim’s engi-neers developed state-of-the-art structures to protect these pins against ESD of ±15kV without damage. The ESD structures withstand high ESD in all states: normal operation, shutdown, and powered down. After an ESD event, Maxim’s MAX481E, MAX483E, MAX485E, MAX487E–MAX491E, and MAX1487E keep working without latchup.ESD protection can be tested in various ways; the transmitter outputs and receiver inputs of this product family are characterized for protection to ±15kV using the Human Body Model.Other ESD test methodologies include IEC10004-2 con-tact discharge and IEC1000-4-2 air-gap discharge (for-merly IEC801-2).ESD Test Conditions ESD performance depends on a variety of conditions. Contact Maxim for a reliability report that documents test set-up, test methodology, and test results.Human Body Model Figure 4 shows the Human Body Model, and Figure 5 shows the current waveform it generates when dis-charged into a low impedance. This model consists of a 100pF capacitor charged to the ESD voltage of inter-est, which is then discharged into the test device through a 1.5kΩresistor.IEC1000-4-2 The IEC1000-4-2 standard covers ESD testing and per-formance of finished equipment; it does not specifically refer to integrated circuits (Figure 6).MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers_______________________________________________________________________________________9M A X 481E /M A X 483E /M A X 485E /M A X 487E –M A X 491E /M A X 1487E±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers10______________________________________________________________________________________Figure 8. Driver DC Test LoadFigure 9. Receiver Timing Test LoadMAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers______________________________________________________________________________________11Figure 10. Driver/Receiver Timing Test Circuit Figure 11. Driver Timing Test LoadFigure 12. Driver Propagation DelaysFigure 13. Driver Enable and Disable Times (except MAX488E and MAX490E)Figure 14. Receiver Propagation DelaysFigure 15. Receiver Enable and Disable Times (except MAX488E and MAX490E)M A X 481E /M A X 483E /M A X 485E /M A X 487E –M A X 491E /M A X 1487E±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers12______________________________________________________________________________________The major difference between tests done using the Human Body Model and IEC1000-4-2 is higher peak current in IEC1000-4-2, because series resistance is lower in the IEC1000-4-2 model. Hence, the ESD with-stand voltage measured to IEC1000-4-2 is generally lower than that measured using the Human Body Model. Figure 7 shows the current waveform for the 8kV IEC1000-4-2 ESD contact-discharge test.The air-gap test involves approaching the device with a charged probe. The contact-discharge method connects the probe to the device before the probe is energized.Machine ModelThe Machine Model for ESD tests all pins using a 200pF storage capacitor and zero discharge resis-tance. Its objective is to emulate the stress caused by contact that occurs with handling and assembly during manufacturing. Of course, all pins require this protec-tion during manufacturing—not just inputs and outputs.Therefore,after PC board assembly,the Machine Model is less relevant to I/O ports.MAX487E/MAX1487E:128 Transceivers on the BusThe 48k Ω, 1/4-unit-load receiver input impedance of the MAX487E and MAX1487E allows up to 128 transceivers on a bus, compared to the 1-unit load (12k Ωinput impedance) of standard RS-485 drivers (32 transceivers maximum). Any combination of MAX487E/MAX1487E and other RS-485 transceivers with a total of 32 unit loads or less can be put on the bus. The MAX481E,MAX483E, MAX485E, and MAX488E–MAX491E have standard 12k Ωreceiver input impedance.MAX483E/MAX487E/MAX488E/MAX489E:Reduced EMI and Reflections The MAX483E and MAX487E–MAX489E are slew-rate limited, minimizing EMI and reducing reflections caused by improperly terminated cables. Figure 16shows the driver output waveform and its Fourier analy-sis of a 150kHz signal transmitted by a MAX481E,MAX485E, MAX490E, MAX491E, or MAX1487E. High-frequency harmonics with large amplitudes are evident.Figure 17 shows the same information displayed for a MAX483E, MAX487E, MAX488E, or MAX489E transmit-ting under the same conditions. Figure 17’s high-fre-quency harmonics have much lower amplitudes, and the potential for EMI is significantly reduced.Low-Power Shutdown Mode (MAX481E/MAX483E/MAX487E)A low-power shutdown mode is initiated by bringing both RE high and DE low. The devices will not shut down unless both the driver and receiver are disabled.In shutdown, the devices typically draw only 0.5µA of supply current.RE and DE may be driven simultaneously; the parts are guaranteed not to enter shutdown if RE is high and DE is low for less than 50ns. If the inputs are in this state for at least 600ns, the parts are guaranteed to enter shutdown.For the MAX481E, MAX483E, and MAX487E, the t ZH and t ZL enable times assume the part was not in the low-power shutdown state (the MAX485E, MAX488E–MAX491E, and MAX1487E can not be shut down). The t ZH(SHDN)and t ZL(SHDN)enable times assume the parts were shut down (see Electrical Characteristics ).500kHz/div0Hz5MHz 10dB/div Figure 16. Driver Output Waveform and FFT Plot ofMAX485E/MAX490E/MAX491E/MAX1487E Transmitting a 150kHz Signal500kHz/div0Hz5MHz10dB/divFigure 17. Driver Output Waveform and FFT Plot ofMAX483E/MAX487E–MAX489E Transmitting a 150kHz SignalIt takes the drivers and receivers longer to become enabled from the low-power shutdown state (t ZH(SHDN), t ZL(SHDN)) than from the operating mode (t ZH, t ZL). (The parts are in operating mode if the RE, DE inputs equal a logical 0,1 or 1,1 or 0, 0.)Driver Output Protection Excessive output current and power dissipation caused by faults or by bus contention are prevented by two mechanisms. A foldback current limit on the output stage provides immediate protection against short circuits over the whole common-mode voltage range (see Typical Operating Characteristics). In addition, a thermal shut-down circuit forces the driver outputs into a high-imped-ance state if the die temperature rises excessively.Propagation Delay Many digital encoding schemes depend on the differ-ence between the driver and receiver propagation delay times. Typical propagation delays are shown in Figures 19–22 using Figure 18’s test circuit.The difference in receiver delay times, t PLH- t PHL, is typically under 13ns for the MAX481E, MAX485E, MAX490E, MAX491E, and MAX1487E, and is typically less than 100ns for the MAX483E and MAX487E–MAX489E.The driver skew times are typically 5ns (10ns max) for the MAX481E, MAX485E, MAX490E, MAX491E, and MAX1487E, and are typically 100ns (800ns max) for the MAX483E and MAX487E–MAX489E.Typical Applications The MAX481E, MAX483E, MAX485E, MAX487E–MAX491E, and MAX1487E transceivers are designed for bidirectional data communications on multipoint bus transmission lines. Figures 25 and 26 show typical net-work application circuits. These parts can also be used as line repeaters, with cable lengths longer than 4000 feet. To minimize reflections, the line should be terminated at both ends in its characteristic impedance, and stub lengths off the main line should be kept as short as possi-ble. The slew-rate-limited MAX483E and MAX487E–MAX489E are more tolerant of imperfect termination. Bypass the V CC pin with 0.1µF.Isolated RS-485 For isolated RS-485 applications, see the MAX253 and MAX1480 data sheets.Line Length vs. Data Rate The RS-485/RS-422 standard covers line lengths up to 4000 feet. Figures 23 and 24 show the system differen-tial voltage for the parts driving 4000 feet of 26AWG twisted-pair wire at 110kHz into 100Ωloads.Figure 18. Receiver Propagation Delay Test CircuitMAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers ______________________________________________________________________________________13M A X 481E /M A X 483E /M A X 485E /M A X 487E –M A X 491E /M A X 1487E±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers14______________________________________________________________________________________25ns/div 5V/divRO B A500mV/div Figure 19. MAX481E/MAX485E/MAX490E/MAX1487E Receiver t PHL25ns/div5V/div ROBA500mV/divFigure 20. MAX481E/MAX485E/MAX490E/MAX491E/MAX1487E Receiver t PLH200ns/div 5V/divRO B A500mV/div Figure 21. MAX483E/MAX487E–MAX489E Receiver t PHL200ns/div5V/div ROBA500mV/divFigure 22. MAX483E/MAX487E–MAX489E Receiver t PLH2µs/div DO 0V0V5V5V -1V 0DIV A - V BFigure 23. MAX481E/MAX485E/MAX490E/MAX491E/MAX1487E System Differential Voltage at 110kHz Driving 4000ft of Cable 2µs/divDO0V0V 5V 5V -1V1V0DIV B - V AFigure 24. MAX483E/MAX1487E–MAX489E System Differential Voltage at 110kHz Driving 4000ft of CableMAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers______________________________________________________________________________________15Figure 26. MAX488E–MAX491E Full-Duplex RS-485 NetworkFigure 25. MAX481E/MAX483E/MAX485E/MAX487E/MAX1487E Typical Half-Duplex RS-485 NetworkM A X 481E /M A X 483E /M A X 485E /M A X 487E –M A X 491E /M A X 1487E±15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.16____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600©2003 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.Package InformationFor the latest package outline information, go to /packages .Ordering Information (continued)Selector GuideChip InformationTRANSISTOR COUNT: 295。

MAX485中文数据手册资料

MAX485中文资料2009-11-28 14:49MAX485中文资料，MAX485 PDF,DATASHEET,电路图，通讯程序内容介绍：MAX481、MAX483、MAX485、MAX487-MAX491以及MAX1487是用于RS-485与RS-422通信的低功耗收发器，每个器件中都具有一个驱动器和一个接收器。

MAX483、MAX487、MAX488以及MAX489具有限摆率驱动器，可以减小EMI，并降低由不恰当的终端匹配电缆引起的反射，实现最高250kbps 的无差错数据传输。

MAX481、MAX485、MAX490、MAX491、MAX1487的驱动器摆率不受限制，可以实现最高2.5Mbps的传输速率。

这些收发器在驱动器禁用的空载或满载状态下，吸取的电源电流在120(A 至500(A 之间。

另外，MAX481、MAX483与MAX487具有低电流关断模式，仅消耗0.1µA。

所有器件都工作在5V单电源下。

驱动器具有短路电流限制，并可以通过热关断电路将驱动器输出置为高阻状态，防止过度的功率损耗。

接收器输入具有失效保护特性，当输入开路时，可以确保逻辑高电平输出。

MAX481,MAX483,MAX485,MAX487,MAX1487引脚（管脚）图及工作电路MAX485通讯程序与MAX232通讯程序在本质上是一样的，只是MAX485通讯程序需要加上通讯方向控制。

下面是基于mega128 16AU的485通信中断接收的程序，调试通过,晶振为外部16M,MAX485的DE和RE短接连PC0口，程序如下：#define SEND_485 PORTC|=0x01#define READ_485 PORTC&=0xfevoid Usart1_init(void) //16Mhz频率，设置波特率9.6k，8位数据位，无校验，接收发送使能，1位停止位{UBRR1H=0;UBRR1L=103;UCSR1B=(1<<RXCIE1)|(1<<RXEN1)|(1<<TXEN1); //发送接收使能，使用中断方式，UCSR1C=(1<<UCSZ10)|(1<<UCSZ11); //0x06 8位数据，1位停止位，无校验}void Usart1_transmit(unsigned char c) //查询方式发送接收字符函数{SEND_485;DelayBus();DelayBus();DelayBus();while( !(UCSR1A&(1<<UDRE1)));//等待发送缓冲区为空UDR1=c;while(!(UCSR1A&(1<<TXC1)));// UDCR0=c;UCSR1A |= _BV(TXC1);//将发送结束标志位清零// SET_BIT(UCSR1A,);READ_485;direction++;}SIGNAL(SIG_UART1_RECV)//serial port 1 {if(UCSR1A&(1<<RXC1)){rec1buff=UDR1;rec1_flag=1;。

MAX3232EEAE+T中文资料

A proprietary low-dropout transmitter output stage delivers true RS-232 performance from a +3.0V to +5.5V power supply, using an internal dual charge pump. The charge pump requires only four small 0.1µF capacitors for operation from a +3.3V supply. Each device guarantees operation at data rates of 250kbps while maintaining RS-232 output levels. The MAX3237E guarantees operation at 250kbps in the normal operating mode and 1Mbps in the MegaBaud™ operating mode, while maintaining RS-232compliant output levels.
Battery-Powered Equipment Cell Phones Cell-Phone Data Cables Notebook, Subnotebook, and Palmtop Computers
Applications
Printers Smart Phones xDSL Modems
MAX3222EEPN -40°C to +85°C 18 Plastic DIP —
MAX3232ECAE 0°C to +70°C 16 SSOP
—

MEMORY存储芯片MAX4051ACSE中文规格书

(V CC = +3.3V, T A = +25°C)Note 1: ∆V OD and ∆V OC are the changes in V OD and V OC , respectively, when the DI input changes state.Note 2: Measured on |t PLH (Y) - t PHL (Y)| and |t PLH (Z) - t PHL (Z)|.Note 3: The transceivers are put into shutdown by bringing RE high and DE low. If the inputs are in this state for less than 80ns, the parts are guaranteed not to enter shutdown. If the inputs are in this state for at least 300ns, the parts are guaranteed tohave entered shutdown. See Low-Power Shutdown Mode section.PARAMETERSYMBOL CONDITIONS MIN TYP MAX UNITS Time to Shutdownt SHDN MAX3483E/MAX3485E/MAX3486E/MAX3491E only (Note 3)80190300ns Receiver Propagation Delay,Low-to-High Levelt RPLH V ID = 0 to 3.0, C L = 15pF, Figure 11256290ns MAX3483E/MAX3488E 2575120Receiver Propagation Delay,High-to-Low Levelt RPHL V ID = 0 to 3.0, C L = 15pF, Figure 11256290ns MAX3483E/MAX3488E 2575120|t PLH - t PHL | ReceiverPropagation Delay Skewt RPDS V ID = 0 to 3.0, C L = 15pF, Figure 116±10ns MAX3483E/MAX3488E 12±20Receiver Output Enable Timeto Low Levelt PRZL C L = 15pF, Figure 12,MAX3483E/85E/86E/91E only 2550ns Receiver Output Enable Timeto High Levelt PRZH C L = 15pF, Figure 12,MAX3483E/85E/86E/91E only 2550ns Receiver Output DisableTime from High Levelt PRHZ C L = 15pF, Figure 12,MAX3483E/85E/86E/91E only 2545ns Receiver Output DisableTime from Low Levelt PRLZ C L = 15pF, Figure 12,MAX3483E/85E/86E/91E only 2545ns Receiver Output Enable Timefrom Shutdown to Low Levelt PRSL C L = 15pF, Figure 12,MAX3483E/85E/86E/91E only 7201400ns Receiver Output Enable Timefrom Shutdown to High Level t PRSH C L = 15pF, Figure 12,MAX3483E/85E/86E/91E only 7201400nsMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers Receiver Switching CharacteristicsGeneral DescriptionDevices in the MAX3483E family (MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E) are ±15kV ESD-protected, +3.3V, low-power transceivers for RS-485 and RS-422 communications. Each device con-tains one driver and one receiver. The MAX3483E and MAX3488E feature slew-rate-limited drivers that minimize EMI and reduce reflections caused by improperly termi-nated cables, allowing error-free data transmission at data rates up to 250kbps. The partially slew-rate-limited MAX3486E transmits up to 2.5Mbps. The MAX3485E, MAX3490E, and MAX3491E transmit at up to 12Mbps.All devices feature enhanced electrostatic discharge (ESD) protection. All transmitter outputs and receiver inputs are protected to ±15kV using IEC 1000-4-2 Air-Gap Discharge, ±8kV using IEC 1000-4-2 Contact Discharge, and ±15kV using the Human Body Model.Drivers are short-circuit current limited and are protected against excessive power dissipation by thermal shutdown circuitry that places the driver outputs into a high-impedance state. The receiver input has a fail-safe feature that guar-antees a logic-high output if both inputs are open circuit.The MAX3488E, MAX3490E, and MAX3491E feature full-duplex communication, while the MAX3483E, MAX3485E, and MAX3486E are designed for half-duplex communication.Applications ●Telecommunications ●Industrial-Control Local Area Networks ●Transceivers for EMI-Sensitive Applications ●Integrated Services Digital Networks ●Packet Switching Features ●ESD Protection for RS-485 I/O Pins •±15kV—Human Body Model •±8kV—IEC 1000-4-2, Contact Discharge •±15kV—IEC 1000-4-2, Air-Gap Discharge ●Operate from a Single +3.3V Supply—No Charge Pump Required ●Interoperable with +5V Logic ●Guaranteed 12Mbps Data Rate (MAX3485E/MAX3490E/MAX3491E)●Slew-Rate Limited for Errorless Data Transmission (MAX3483E/MAX3488E)●2nA Low-Current Shutdown Mode (MAX3483E/MAX3485E/MAX3486E/MAX3491E)●-7V to +12V Common-Mode Input Voltage Range ●Full-Duplex and Half-Duplex Versions Available ●Industry-Standard 75176 Pinout (MAX3483E/MAX3485E/MAX3486E)●Current-Limiting and Thermal Shutdown for Driver Overload Protection Ordering Information continued at end of data sheet.PARTTEMP . RANGE PIN-PACKAGE MAX3483E CSA0°C to+70°C 8 SO MAX3483ECPA0°C to+70°C 8 Plastic DIP MAX3483EESA-40°C to+85°C 8 SO MAX3483EEPA -40°C to+85°C 8 Plastic DIP PART NUMBERGUARANTEED DATA RATE (Mbps)SUPPLY VOLTAGE (V)HALF/FULL DUPLEX SLEW-RATE LIMITED DRIVER/RECEIVER ENABLE SHUTDOWN CURRENT (nA)±15kV ESD PROTECTION PIN COUNT MAX3483E0.25 3.0 to 3.6Half Yes Yes 2Yes 8MAX3485E12Half No Yes 2Yes 8MAX3486E2.5Half Yes Yes 2Yes 8MAX3488E0.25Full Yes No —Yes 8MAX3490E12Full No No —Yes 8MAX3491E 12Full No Yes 2Yes 14MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers Selector GuideOrdering InformationClick here for production status of specific part numbers.。

MAX485CPA+中文资料

For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .General DescriptionThe MAX481, MAX483, MAX485, MAX487–MAX491, and MAX1487 are low-power transceivers for RS-485 and RS-422 communication. Each part contains one driver and one receiver. The MAX483, MAX487, MAX488, and MAX489feature reduced slew-rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables,thus allowing error-free data transmission up to 250kbps.The driver slew rates of the MAX481, MAX485, MAX490,MAX491, and MAX1487 are not limited, allowing them to transmit up to 2.5Mbps.These transceivers draw between 120µA and 500µA of supply current when unloaded or fully loaded with disabled drivers. Additionally, the MAX481, MAX483, and MAX487have a low-current shutdown mode in which they consume only 0.1µA. All parts operate from a single 5V supply.Drivers are short-circuit current limited and are protected against excessive power dissipation by thermal shutdown circuitry that places the driver outputs into a high-imped-ance state. The receiver input has a fail-safe feature that guarantees a logic-high output if the input is open circuit.The MAX487 and MAX1487 feature quarter-unit-load receiver input impedance, allowing up to 128 MAX487/MAX1487 transceivers on the bus. Full-duplex communi-cations are obtained using the MAX488–MAX491, while the MAX481, MAX483, MAX485, MAX487, and MAX1487are designed for half-duplex applications.________________________ApplicationsLow-Power RS-485 Transceivers Low-Power RS-422 Transceivers Level TranslatorsTransceivers for EMI-Sensitive Applications Industrial-Control Local Area Networks__Next Generation Device Features♦For Fault-Tolerant ApplicationsMAX3430: ±80V Fault-Protected, Fail-Safe, 1/4Unit Load, +3.3V, RS-485 TransceiverMAX3440E–MAX3444E: ±15kV ESD-Protected,±60V Fault-Protected, 10Mbps, Fail-Safe, RS-485/J1708 Transceivers♦For Space-Constrained ApplicationsMAX3460–MAX3464: +5V, Fail-Safe, 20Mbps,Profibus RS-485/RS-422 TransceiversMAX3362: +3.3V, High-Speed, RS-485/RS-422Transceiver in a SOT23 PackageMAX3280E–MAX3284E: ±15kV ESD-Protected,52Mbps, +3V to +5.5V, SOT23, RS-485/RS-422,True Fail-Safe ReceiversMAX3293/MAX3294/MAX3295: 20Mbps, +3.3V,SOT23, RS-855/RS-422 Transmitters ♦For Multiple Transceiver ApplicationsMAX3030E–MAX3033E: ±15kV ESD-Protected,+3.3V, Quad RS-422 Transmitters ♦For Fail-Safe ApplicationsMAX3080–MAX3089: Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422Transceivers♦For Low-Voltage ApplicationsMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E: +3.3V Powered, ±15kV ESD-Protected, 12Mbps, Slew-Rate-Limited,True RS-485/RS-422 TransceiversMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers______________________________________________________________Selection Table19-0122; Rev 8; 10/03Ordering Information appears at end of data sheet.M A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSSupply Voltage (V CC ).............................................................12V Control Input Voltage (RE , DE)...................-0.5V to (V CC + 0.5V)Driver Input Voltage (DI).............................-0.5V to (V CC + 0.5V)Driver Output Voltage (A, B)...................................-8V to +12.5V Receiver Input Voltage (A, B).................................-8V to +12.5V Receiver Output Voltage (RO).....................-0.5V to (V CC +0.5V)Continuous Power Dissipation (T A = +70°C)8-Pin Plastic DIP (derate 9.09mW/°C above +70°C)....727mW 14-Pin Plastic DIP (derate 10.00mW/°C above +70°C)..800mW 8-Pin SO (derate 5.88mW/°C above +70°C).................471mW14-Pin SO (derate 8.33mW/°C above +70°C)...............667mW 8-Pin µMAX (derate 4.1mW/°C above +70°C)..............830mW 8-Pin CERDIP (derate 8.00mW/°C above +70°C).........640mW 14-Pin CERDIP (derate 9.09mW/°C above +70°C).......727mW Operating Temperature RangesMAX4_ _C_ _/MAX1487C_ A...............................0°C to +70°C MAX4__E_ _/MAX1487E_ A.............................-40°C to +85°C MAX4__MJ_/MAX1487MJA...........................-55°C to +125°C Storage Temperature Range.............................-65°C to +160°C Lead Temperature (soldering, 10sec).............................+300°CDC ELECTRICAL CHARACTERISTICS(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.V V IN = -7VV IN = 12V V IN = -7V V IN = 12V Input Current (A, B)I IN2V TH k Ω48-7V ≤V CM ≤12V, MAX487/MAX1487R INReceiver Input Resistance -7V ≤V CM ≤12V, all devices except MAX487/MAX1487R = 27Ω(RS-485), Figure 40.4V ≤V O ≤2.4VR = 50Ω(RS-422)I O = 4mA, V ID = -200mV I O = -4mA, V ID = 200mV V CM = 0V-7V ≤V CM ≤12V DE, DI, RE DE, DI, RE MAX487/MAX1487,DE = 0V, V CC = 0V or 5.25VDE, DI, RE R = 27Ωor 50Ω, Figure 4R = 27Ωor 50Ω, Figure 4R = 27Ωor 50Ω, Figure 4DE = 0V;V CC = 0V or 5.25V,all devices except MAX487/MAX1487CONDITIONSk Ω12µA ±1I OZRThree-State (high impedance)Output Current at ReceiverV 0.4V OL Receiver Output Low Voltage 3.5V OH Receiver Output High Voltage mV 70∆V TH Receiver Input Hysteresis V -0.20.2Receiver Differential Threshold Voltage-0.2mA 0.25mA-0.81.01.55V OD2Differential Driver Output (with load)V 2V 5V OD1Differential Driver Output (no load)µA±2I IN1Input CurrentV 0.8V IL Input Low Voltage V 2.0V IH Input High Voltage V 0.2∆V OD Change in Magnitude of Driver Common-Mode Output Voltage for Complementary Output States V 0.2∆V OD Change in Magnitude of Driver Differential Output Voltage for Complementary Output States V 3V OC Driver Common-Mode Output VoltageUNITS MINTYPMAX SYMBOL PARAMETERMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers_______________________________________________________________________________________3SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)DC ELECTRICAL CHARACTERISTICS (continued)(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)ns 103060t PHLDriver Rise or Fall Time Figures 6 and 8, R DIFF = 54Ω, C L1= C L2= 100pF ns MAX490M, MAX491M MAX490C/E, MAX491C/E2090150MAX481, MAX485, MAX1487MAX490M, MAX491MMAX490C/E, MAX491C/E MAX481, MAX485, MAX1487Figures 6 and 8, R DIFF = 54Ω,C L1= C L2= 100pF MAX481 (Note 5)Figures 5 and 11, C RL = 15pF, S2 closedFigures 5 and 11, C RL = 15pF, S1 closed Figures 5 and 11, C RL = 15pF, S2 closed Figures 5 and 11, C RL = 15pF, S1 closed Figures 6 and 10, R DIFF = 54Ω,C L1= C L2= 100pFFigures 6 and 8,R DIFF = 54Ω,C L1= C L2= 100pF Figures 6 and 10,R DIFF = 54Ω,C L1= C L2= 100pF CONDITIONS ns 510t SKEW ns50200600t SHDNTime to ShutdownMbps 2.5f MAX Maximum Data Rate ns 2050t HZ Receiver Disable Time from High ns 103060t PLH 2050t LZ Receiver Disable Time from Low ns 2050t ZH Driver Input to Output Receiver Enable to Output High ns 2050t ZL Receiver Enable to Output Low 2090200ns ns 134070t HZ t SKD Driver Disable Time from High |t PLH - t PHL |DifferentialReceiver Skewns 4070t LZ Driver Disable Time from Low ns 4070t ZL Driver Enable to Output Low 31540ns51525ns 31540t R , t F 2090200Driver Output Skew to Output t PLH , t PHL Receiver Input to Output4070t ZH Driver Enable to Output High UNITS MIN TYP MAX SYMBOL PARAMETERFigures 7 and 9, C L = 100pF, S2 closed Figures 7 and 9, C L = 100pF, S1 closed Figures 7 and 9, C L = 15pF, S1 closed Figures 7 and 9, C L = 15pF, S2 closedM A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 4_______________________________________________________________________________________SWITCHING CHARACTERISTICS—MAX483, MAX487/MAX488/MAX489(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487 (continued)(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)3001000Figures 7 and 9, C L = 100pF, S2 closed Figures 7 and 9, C L = 100pF, S1 closed Figures 5 and 11, C L = 15pF, S2 closed,A - B = 2VCONDITIONSns 40100t ZH(SHDN)Driver Enable from Shutdown toOutput High (MAX481)nsFigures 5 and 11, C L = 15pF, S1 closed,B - A = 2Vt ZL(SHDN)Receiver Enable from Shutdownto Output Low (MAX481)ns 40100t ZL(SHDN)Driver Enable from Shutdown toOutput Low (MAX481)ns 3001000t ZH(SHDN)Receiver Enable from Shutdownto Output High (MAX481)UNITS MINTYP MAX SYMBOLPARAMETERt PLH t SKEW Figures 6 and 8, R DIFF = 54Ω,C L1= C L2= 100pFt PHL Figures 6 and 8, R DIFF = 54Ω,C L1= C L2= 100pFDriver Input to Output Driver Output Skew to Output ns 100800ns ns 2000MAX483/MAX487, Figures 7 and 9,C L = 100pF, S2 closedt ZH(SHDN)Driver Enable from Shutdown to Output High2502000ns2500MAX483/MAX487, Figures 5 and 11,C L = 15pF, S1 closedt ZL(SHDN)Receiver Enable from Shutdown to Output Lowns 2500MAX483/MAX487, Figures 5 and 11,C L = 15pF, S2 closedt ZH(SHDN)Receiver Enable from Shutdown to Output Highns 2000MAX483/MAX487, Figures 7 and 9,C L = 100pF, S1 closedt ZL(SHDN)Driver Enable from Shutdown to Output Lowns 50200600MAX483/MAX487 (Note 5) t SHDN Time to Shutdownt PHL t PLH , t PHL < 50% of data period Figures 5 and 11, C RL = 15pF, S2 closed Figures 5 and 11, C RL = 15pF, S1 closed Figures 5 and 11, C RL = 15pF, S2 closed Figures 5 and 11, C RL = 15pF, S1 closed Figures 7 and 9, C L = 15pF, S2 closed Figures 6 and 10, R DIFF = 54Ω,C L1= C L2= 100pFFigures 7 and 9, C L = 15pF, S1 closed Figures 7 and 9, C L = 100pF, S1 closed Figures 7 and 9, C L = 100pF, S2 closed CONDITIONSkbps 250f MAX 2508002000Maximum Data Rate ns 2050t HZ Receiver Disable Time from High ns 25080020002050t LZ Receiver Disable Time from Low ns 2050t ZH Receiver Enable to Output High ns 2050t ZL Receiver Enable to Output Low ns ns 1003003000t HZ t SKD Driver Disable Time from High I t PLH - t PHL I DifferentialReceiver SkewFigures 6 and 10, R DIFF = 54Ω,C L1= C L2= 100pFns 3003000t LZ Driver Disable Time from Low ns 2502000t ZL Driver Enable to Output Low ns Figures 6 and 8, R DIFF = 54Ω,C L1= C L2= 100pFns 2502000t R , t F 2502000Driver Rise or Fall Time ns t PLH Receiver Input to Output2502000t ZH Driver Enable to Output High UNITS MIN TYP MAX SYMBOL PARAMETERMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers_______________________________________________________________________________________530002.5OUTPUT CURRENT vs.RECEIVER OUTPUT LOW VOLTAGE525M A X 481-01OUTPUT LOW VOLTAGE (V)O U T P U T C U R R E N T (m A )1.515100.51.02.0203540450.90.1-50-252575RECEIVER OUTPUT LOW VOLTAGE vs.TEMPERATURE0.30.7TEMPERATURE (°C)O U T P U TL O W V O L T A G E (V )500.50.80.20.60.40100125-20-41.5 2.0 3.0 5.0OUTPUT CURRENT vs.RECEIVER OUTPUT HIGH VOLTAGE-8-16M A X 481-02OUTPUT HIGH VOLTAGE (V)O U T P U T C U R R E N T (m A )2.5 4.0-12-18-6-14-10-203.54.5 4.83.2-50-252575RECEIVER OUTPUT HIGH VOLTAGE vs.TEMPERATURE3.64.4TEMPERATURE (°C)O U T P UT H I G H V O L T A G E (V )0504.04.63.44.23.83.01001259000 1.0 3.0 4.5DRIVER OUTPUT CURRENT vs.DIFFERENTIAL OUTPUT VOLTAGE1070M A X 481-05DIFFERENTIAL OUTPUT VOLTAGE (V)O U T P U T C U R R E N T (m A )2.0 4.05030806040200.5 1.5 2.53.5 2.31.5-50-2525125DRIVER DIFFERENTIAL OUTPUT VOLTAGEvs. TEMPERATURE1.72.1TEMPERATURE (°C)D I F FE R E N T I A L O U T P U T V O L T A G E (V )751.92.21.62.01.8100502.4__________________________________________Typical Operating Characteristics(V CC = 5V, T A = +25°C, unless otherwise noted.)NOTES FOR ELECTRICAL/SWITCHING CHARACTERISTICSNote 1:All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to deviceground unless otherwise specified.Note 2:All typical specifications are given for V CC = 5V and T A = +25°C.Note 3:Supply current specification is valid for loaded transmitters when DE = 0V.Note 4:Applies to peak current. See Typical Operating Characteristics.Note 5:The MAX481/MAX483/MAX487 are put into shutdown by bringing RE high and DE low. If the inputs are in this state for lessthan 50ns, the parts are guaranteed not to enter shutdown. If the inputs are in this state for at least 600ns, the parts are guaranteed to have entered shutdown. See Low-Power Shutdown Mode section.M A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 6___________________________________________________________________________________________________________________Typical Operating Characteristics (continued)(V CC = 5V, T A = +25°C, unless otherwise noted.)120008OUTPUT CURRENT vs.DRIVER OUTPUT LOW VOLTAGE20100M A X 481-07OUTPUT LOW VOLTAGE (V)O U T P U T C U R R E N T (m A )6604024801012140-1200-7-5-15OUTPUT CURRENT vs.DRIVER OUTPUT HIGH VOLTAGE-20-80M A X 481-08OUTPUT HIGH VOLTAGE (V)O U T P U T C U R R E N T (m A )-31-603-6-4-2024-100-40100-40-60-2040100120MAX1487SUPPLY CURRENT vs. TEMPERATURE300TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )20608050020060040000140100-50-2550100MAX481/MAX485/MAX490/MAX491SUPPLY CURRENT vs. TEMPERATURE300TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )257550020060040000125100-50-2550100MAX483/MAX487–MAX489SUPPLY CURRENT vs. TEMPERATURE300TEMPERATURE (°C)S U P P L Y C U R R E N T (µA )257550020060040000125MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers_______________________________________________________________________________________7______________________________________________________________Pin DescriptionFigure 1. MAX481/MAX483/MAX485/MAX487/MAX1487 Pin Configuration and Typical Operating CircuitM A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487__________Applications InformationThe MAX481/MAX483/MAX485/MAX487–MAX491 and MAX1487 are low-power transceivers for RS-485 and RS-422 communications. The MAX481, MAX485, MAX490,MAX491, and MAX1487 can transmit and receive at data rates up to 2.5Mbps, while the MAX483, MAX487,MAX488, and MAX489 are specified for data rates up to 250kbps. The MAX488–MAX491 are full-duplex trans-ceivers while the MAX481, MAX483, MAX485, MAX487,and MAX1487 are half-duplex. In addition, Driver Enable (DE) and Receiver Enable (RE) pins are included on the MAX481, MAX483, MAX485, MAX487, MAX489,MAX491, and MAX1487. When disabled, the driver and receiver outputs are high impedance.MAX487/MAX1487:128 Transceivers on the BusThe 48k Ω, 1/4-unit-load receiver input impedance of the MAX487 and MAX1487 allows up to 128 transceivers on a bus, compared to the 1-unit load (12k Ωinput impedance) of standard RS-485 drivers (32 trans-ceivers maximum). Any combination of MAX487/MAX1487 and other RS-485 transceivers with a total of 32 unit loads or less can be put on the bus. The MAX481/MAX483/MAX485 and MAX488–MAX491 have standard 12k ΩReceiver Input impedance.Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 8_______________________________________________________________________________________Figure 2. MAX488/MAX490 Pin Configuration and Typical Operating CircuitFigure 3. MAX489/MAX491 Pin Configuration and Typical Operating CircuitMAX483/MAX487/MAX488/MAX489:Reduced EMI and ReflectionsThe MAX483 and MAX487–MAX489 are slew-rate limit-ed, minimizing EMI and reducing reflections caused by improperly terminated cables. Figure 12 shows the dri-ver output waveform and its Fourier analysis of a 150kHz signal transmitted by a MAX481, MAX485,MAX490, MAX491, or MAX1487. High-frequency har-monics with large amplitudes are evident. Figure 13shows the same information displayed for a MAX483,MAX487, MAX488, or MAX489 transmitting under the same conditions. Figure 13’s high-frequency harmonics have much lower amplitudes, and the potential for EMI is significantly reduced.MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers_______________________________________________________________________________________9_________________________________________________________________Test CircuitsFigure 4. Driver DC Test Load Figure 5. Receiver Timing Test LoadFigure 6. Driver/Receiver Timing Test Circuit Figure 7. Driver Timing Test LoadM A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 10_______________________________________________________Switching Waveforms_________________Function Tables (MAX481/MAX483/MAX485/MAX487/MAX1487)Figure 8. Driver Propagation DelaysFigure 9. Driver Enable and Disable Times (except MAX488 and MAX490)Figure 10. Receiver Propagation DelaysFigure 11. Receiver Enable and Disable Times (except MAX488and MAX490)Table 1. TransmittingTable 2. ReceivingLow-Power Shutdown Mode (MAX481/MAX483/MAX487)A low-power shutdown mode is initiated by bringing both RE high and DE low. The devices will not shut down unless both the driver and receiver are disabled.In shutdown, the devices typically draw only 0.1µA of supply current.RE and DE may be driven simultaneously; the parts are guaranteed not to enter shutdown if RE is high and DE is low for less than 50ns. If the inputs are in this state for at least 600ns, the parts are guaranteed to enter shutdown.For the MAX481, MAX483, and MAX487, the t ZH and t ZL enable times assume the part was not in the low-power shutdown state (the MAX485/MAX488–MAX491and MAX1487 can not be shut down). The t ZH(SHDN)and t ZL(SHDN)enable times assume the parts were shut down (see Electrical Characteristics ).It takes the drivers and receivers longer to become enabled from the low-power shutdown state (t ZH(SHDN ), t ZL(SHDN)) than from the operating mode (t ZH , t ZL ). (The parts are in operating mode if the –R —E –,DE inputs equal a logical 0,1 or 1,1 or 0, 0.)Driver Output ProtectionExcessive output current and power dissipation caused by faults or by bus contention are prevented by two mechanisms. A foldback current limit on the output stage provides immediate protection against short cir-cuits over the whole common-mode voltage range (see Typical Operating Characteristics ). In addition, a ther-mal shutdown circuit forces the driver outputs into a high-impedance state if the die temperature rises excessively.Propagation DelayMany digital encoding schemes depend on the differ-ence between the driver and receiver propagation delay times. Typical propagation delays are shown in Figures 15–18 using Figure 14’s test circuit.The difference in receiver delay times, | t PLH - t PHL |, is typically under 13ns for the MAX481, MAX485,MAX490, MAX491, and MAX1487 and is typically less than 100ns for the MAX483 and MAX487–MAX489.The driver skew times are typically 5ns (10ns max) for the MAX481, MAX485, MAX490, MAX491, and MAX1487, and are typically 100ns (800ns max) for the MAX483 and MAX487–MAX489.MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers______________________________________________________________________________________1110dB/div0Hz5MHz500kHz/div10dB/div0Hz5MHz500kHz/divFigure 12. Driver Output Waveform and FFT Plot of MAX481/MAX485/MAX490/MAX491/MAX1487 Transmitting a 150kHz SignalFigure 13. Driver Output Waveform and FFT Plot of MAX483/MAX487–MAX489 Transmitting a 150kHz SignalM A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 12______________________________________________________________________________________V CC = 5V T A = +25°CV CC = 5V T A = +25°CV CC = 5V T A = +25°CV CC = 5V T A = +25°CFigure 14. Receiver Propagation Delay Test CircuitFigure 15. MAX481/MAX485/MAX490/MAX491/MAX1487Receiver t PHLFigure 16. MAX481/MAX485/MAX490/MAX491/MAX1487Receiver t PLHPHL Figure 18. MAX483, MAX487–MAX489 Receiver t PLHLine Length vs. Data RateThe RS-485/RS-422 standard covers line lengths up to 4000 feet. For line lengths greater than 4000 feet, see Figure 23.Figures 19 and 20 show the system differential voltage for the parts driving 4000 feet of 26AWG twisted-pair wire at 110kHz into 120Ωloads.Typical ApplicationsThe MAX481, MAX483, MAX485, MAX487–MAX491, and MAX1487 transceivers are designed for bidirectional data communications on multipoint bus transmission lines.Figures 21 and 22 show typical network applications circuits. These parts can also be used as line repeaters, with cable lengths longer than 4000 feet, as shown in Figure 23.To minimize reflections, the line should be terminated at both ends in its characteristic impedance, and stub lengths off the main line should be kept as short as possi-ble. The slew-rate-limited MAX483 and MAX487–MAX489are more tolerant of imperfect termination.MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers______________________________________________________________________________________13DIV Y -V ZRO5V 0V1V0V -1V5V 0V2µs/divFigure 19. MAX481/MAX485/MAX490/MAX491/MAX1487 System Differential Voltage at 110kHz Driving 4000ft of Cable Figure 20. MAX483, MAX487–MAX489 System Differential Voltage at 110kHz Driving 4000ft of CableFigure 21. MAX481/MAX483/MAX485/MAX487/MAX1487 Typical Half-Duplex RS-485 NetworkM A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 14______________________________________________________________________________________Figure 22. MAX488–MAX491 Full-Duplex RS-485 NetworkFigure 23. Line Repeater for MAX488–MAX491Isolated RS-485For isolated RS-485 applications, see the MAX253 and MAX1480 data sheets.MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers______________________________________________________________________________________15_______________Ordering Information_________________Chip TopographiesMAX481/MAX483/MAX485/MAX487/MAX1487N.C. RO 0.054"(1.372mm)0.080"(2.032mm)DE DIGND B N.C.V CCARE * Contact factory for dice specifications.__Ordering Information (continued)M A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 16______________________________________________________________________________________TRANSISTOR COUNT: 248SUBSTRATE CONNECTED TO GNDMAX488/MAX490B RO 0.054"(1.372mm)0.080"(2.032mm)N.C. DIGND Z A V CCYN.C._____________________________________________Chip Topographies (continued)MAX489/MAX491B RO 0.054"(1.372mm)0.080"(2.032mm)DE DIGND Z A V CCYREMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers______________________________________________________________________________________17Package Information(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to /packages .)S O I C N .E P SM A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers 18______________________________________________________________________________________Package Information (continued)(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to /packages .)MAX481/MAX483/MAX485/MAX487–MAX491Low-Power, Slew-Rate-Limited RS-485/RS-422 TransceiversMaxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________19©2003 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.M A X 481/M A X 483/M A X 485/M A X 487–M A X 491/M A X 1487P D I P N .E PSPackage Information (continued)(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to /packages .)。

MAX4081SASA中文资料

The MAX4080/MAX4081 operate from a 4.5V to 76V single supply and draw only 75µA of supply current. These devices are specified over the automotive operating temperature range (-40°C to +125°C) and are available in a space-saving 8-pin µMAX or SO package.
Continuous Power Dissipation (TA = +70°C) 8-Pin µMAX (derate 4.5mW/°C above +70°C) .............362mW 8-Pin SO (derate 5.88mW/°C above +70°C)................471mW
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

MAX4511中文资料

General DescriptionThe MAX4511/MAX4512/MAX4513 are quad, single-pole/single-throw (SPST), fault-protected analog switch-es. They are pin-compatible with the industry-standard nonprotected DG201/DG202/DG213. These new switch-es feature fault-protected inputs and Rail-to-Rail ®signal handling capability. The normally open (NO_) and normally closed (NC_) terminals are protected from overvoltage faults up to 36V during power-up or power-down. During a fault condition, the NO_ or NC_terminal becomes an open circuit and only nanoamperes of leakage current flow from the source, but the switch output (COM_) furnishes up to 10mA of the appropriate polarity supply voltage to the load. This ensures unam-biguous rail-to-rail outputs when a fault begins and ends.On-resistance is 175Ωmax and is matched between switches to 10Ωmax. The off-leakage current is only 0.5nA at +25°C and 10nA at +85°C.The MAX4511 has four normally closed switches. The MAX4512 has four normally open switches. The MAX4513 has two normally closed and two normally open switches.These CMOS switches can operate with dual power supplies ranging from ±4.5V to ±18V or a single supply between +9V and +36V.All digital inputs have +0.8V and +2.4V logic thresh-olds, ensuring both TTL- and CMOS-logic compatibility when using ±15V or a single +12V supply.ApplicationsATE Equipment Data AcquisitionIndustrial and Process-Control Systems AvionicsRedundant/Backup SystemsFeatureso ±40V Fault Protection with Power Off±36V Fault Protection with ±15V Supplies o All Switches Off with Power Off o Rail-to-Rail Signal Handlingo Output Clamped to Appropriate Supply Voltage During Fault Condition; No Transition Glitch o 175Ωmax Signal Paths with ±15V Supplies o No Power-Supply Sequencing Required o ±4.5V to ±18V Dual Supplies +9V to +36V Single Supply o Low Power Consumption, <2mWo Four Separately Controlled SPST Switches o Pin-Compatible with Industry-StandardDG411/DG412/DG413, DG201/DG202/DG213o TTL- and CMOS-Compatible Logic Inputs with Single +9V to +15V or ±15V SuppliesFor free samples & the latest literature: , or phone 1-800-998-8800.For small orders, phone 408-737-7600 ext. 3468.MAX4511/MAX4512/MAX4513Quad, Rail-to-Rail, Fault-Protected,SPST Analog Switches________________________________________________________________Maxim Integrated Products119-4760; Rev 0; 6/98Ordering Information continued at end of data sheet.*Contact factory for dice specifications.Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.Ordering InformationPin Configurations/Functional Diagrams/Truth TablesM A X 4511/M A X 4512/M A X 4513Quad, Rail-to-Rail, Fault-Protected,SPST Analog Switches 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS—Dual Supplies(V+ = +15V, V- = -15V, GND = 0V, T A =T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Note 1:COM_ and IN_ pins are not fault protected. Signals on COM_ or IN_ exceeding V+ or V- are clamped by internal diodes.Limit forward diode current to maximum current rating.Note 2:NC_ and NO_ pins are fault protected. Signals on NC_ or NO_ exceeding -36V to +36V may damage the device. Theselimits apply with power applied to V+ or V-, or ±40V with V+ = V- = 0.(Voltages Referenced to GND)V+........................................................................-0.3V to +44.0V V-.........................................................................-44.0V to +0.3V V+ to V-................................................................-0.3V to +44.0V COM_, IN_ (Note 1)..............................(V- - 0.3V) to (V+ + 0.3V)NC_, NO_ (Note 2)..................................(V+ - 36V) to (V- + 36V)NC_, NO_ to COM_.................................................-36V to +36V Continuous Current into Any Terminal..............................±30mA Peak Current into Any Terminal(pulsed at 1ms, 10% duty cycle)...................................±50mAContinuous Power Dissipation (T A = +70°C) (Note 2)Plastic DIP (derate 10.53mW/°C above +70°C)...........842mW Narrow SO (derate 8.70mW/°C above +70°C).............696mW CERDIP (derate 10.00mW/°C above +70°C)................800mW Operating Temperature RangesMAX451_C_ E......................................................0°C to +70°C MAX451_E_ E...................................................-40°C to +85°C MAX451_MJE .................................................-55°C to +125°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10sec).............................+300°CMAX4511/MAX4512/MAX4513Quad, Rail-to-Rail, Fault-Protected,SPST Analog Switches_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS—Dual Supplies (continued)(V+ = +15V, V- = -15V, GND = 0V, T A =T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.)M A X 4511/M A X 4512/M A X 4513Quad, Rail-to-Rail, Fault-Protected,SPST Analog Switches 4_______________________________________________________________________________________ELECTRICAL CHARACTERISTICS—Dual Supplies (continued)(V+ = +15V, V- = -15V, GND = 0V, T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.)MAX4511/MAX4512/MAX4513Quad, Rail-to-Rail, Fault-Protected,SPST Analog Switches_______________________________________________________________________________________5ELECTRICAL CHARACTERISTICS—Single +12V Supply(V+ = +10.8V to +13.2V, V- = 0, T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.)M A X 4511/M A X 4512/M A X 4513Quad, Rail-to-Rail, Fault-Protected,SPST Analog Switches 6_______________________________________________________________________________________Note 1:COM_ and IN_ pins are not fault protected. Signals on COM_ or IN_ exceeding V+ or V- are clamped by internal diodes.Limit forward diode current to maximum current rating.Note 2:NC_ and NO_ pins are fault protected. Signals on NC_ or NO_ exceeding -36V to +36V may damage the device. These limits apply with power applied to V+ or V-, or ±40V with V+ = V- = 0.Note 3:The algebraic convention is used in this data sheet; the most negative value is shown in the minimum column.Note 4:∆R ON = ∆R ON(MAX)- ∆R ON(MIN).Note 5:Leakage parameters are 100% tested at maximum rated hot temperature and guaranteed by correlation at T A = +25°C.Note 6:Guaranteed by design.Note 7:Off isolation = 20 log10 [ V COM_/ (V NC_or V NO_) ], V COM_= output, V NC_or V NO_= input to off switch.Note 8:Between any two switches.Note 9:Leakage testing for single-supply operation is guaranteed by testing with dual supplies.ELECTRICAL CHARACTERISTICS—Single +12V Supply (continued)(V+ = +10.8V to +13.2V, V- = 0, T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.)MAX4511/MAX4512/MAX4513Quad, Rail-to-Rail, Fault-Protected,SPST Analog Switches_______________________________________________________________________________________7__________________________________________Typical Operating Characteristics(T A = +25°C, unless otherwise noted.)010050250200150300350-20-50-15-105101520SWITCH ON-RESISTANCE vs. V COM (DUAL SUPPLIES)V COM (V)S W I T C H O N -R E S I S T A N C E (Ω)80602040160140100120180200-15-50-1051015SWITCH ON-RESISTANCE vs. V COM AND TEMPERATURE (DUAL SUPPLIES)V COM (V)S W I T C H O N -R E S I S T A N C E (Ω)100010051015202530SWITCH ON-RESISTANCE vs. V COM (SINGLE SUPPLY)V COM (V)S W I T C H O N -R E S I S I T A N C E (Ω)050200150100300350250400046281012SWITCH ON-RESISTANCE vs. V COMAND TEMPERATURE (SINGLE SUPPLY)V COM (V)S W I T C H O N -R E S I S T A N C E (Ω)0300200100700800600500400900100005101520ON AND OFF TIMES vs. SUPPLY VOLTAGESUPPLY VOLTAGE (±V)t O N , t O F F (n s )1p10p100p1n10n 100n-50-25255075100125150I D(ON), I S(OFF), AND I D(OFF) LEAKAGES vs. TEMPERATURETEMPERATURE (°C)L E A K A G E (A )02810641214-15-10-5051015CHARGE INJECTION vs. V COM (DUAL SUPPLIES)V COM (V)Q (p C )010*******500400600-5025-255075100125ON AND OFF TIMES vs. TEMPERATURETEMPERATURE (°C)t O N , t O F F (n s )100300200500400600-50025-255075100125POWER-SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (µA )M A X 4511/M A X 4512/M A X 4513Quad, Rail-to-Rail, Fault-Protected,SPST Analog Switches 8_______________________________________________________________________________________00.51.51.02.52.03.001015520253035LOGIC-LEVEL THRESHOLD vs. V+M A X 4511-10V+ (V)L O G I C -L E V E L T H R E S H O L D (V )Typical Operating Characteristics (continued)(T A = +25°C, unless otherwise noted.)0-10-20-1200.010.11101001000FREQUENCY RESPONSE-90-100-110FREQUENCY (MHz)L O S S (d B )P H A S E (D E G R E E S )-70-80-50-60-30-4012010080-120-60-80-100-20-402006040NAME FUNCTION1, 16,9, 8IN1–IN4Logic Control Digital Inputs 2, 15,10, 7COM1–COM4Analog Switch Common* TerminalsPIN 3, 14,11, 6NO1–NO4orNC1–NC4Analog Switch Fault-Protected NormallyOpen* or Normally Closed* Terminals 4V-Negative Analog Supply Voltage Input.Connect to GND for single-supply operation.13V+Positive Analog and Digital Supply-Voltage Input. Internally connected to substrate.12N.C.No Connection—not internally connected 5GND Ground. Connect to digital ground. (Analog signals have no ground reference.)Pin Description*As long as the voltage on NO_ or NC_ does not exceed V+ or V-, NO_ (or NC_) and COM_ pins are identical and interchange-able. Either may be considered as an input or output; signals pass equally well in either direction.Detailed DescriptionOverview of Traditional Fault-Protected SwitchesThe MAX4511/MAX4512/MAX4513 are fault-protected CMOS analog switches with unusual operation and construction. Traditional fault-protected switches are constructed by three series FETs. This produces good off characteristics, but fairly high on-resistance when the signals are within about 3V of each supply rail. As the voltage on one side of the switch approaches with-in about 3V of either supply rail (a fault condition), the switch impedance becomes higher, limiting the output signal range (on the protected side of the switch) to approximately 3V less than the appropriate polarity supply voltage.During a fault condition, the output current that flows from the protected side of the switch into its load comes from the fault source on the other side of the switch. If the switch is open or the load is extremely high impedance, the input current will be very low. If the switch is on and the load is low impedance,enough current will flow from the source to maintain the load voltage at 3V less than the supply.MAX4511/MAX4512/MAX4513Quad, Rail-to-Rail, Fault-Protected,SPST Analog Switches_______________________________________________________________________________________9Overview of MAX4511/MAX4512/MAX4513The MAX4511/MAX4512/MAX4513 differ considerably from traditional fault-protection switches, with several advantages. First, they are constructed with two paral-lel FETs, allowing very low on-resistance when the switch is on. Second, they allow signals on the NC_ or NO_ pins that are within or slightly beyond the supply rails to be passed through the switch to the COM termi-nal, allowing rail-to-rail signal operation. Third, when a signal on NC_ or NO_ exceeds the supply rails by about 50mV (a fault condition), the voltage on COM_ is limited to the appropriate polarity supply voltage.Operation is identical for both fault polarities. The fault-protection extends to ±36V from GND.During a fault condition, the NO_ or NC_ input pin becomes high impedance regardless of the switch state or load resistance. If the switch is on, the COM_output current is furnished from the V+ or V- pin by “booster” FETs connected to each supply pin. These FETs can typically source or sink up to 10mA.When power is removed, the fault protection is still in effect. In this case, the NO_ or NC_ terminals are a vir-tual open circuit. The fault can be up to ±40V.The COM_ pins are not fault protected; they act as nor-mal CMOS switch pins. If a voltage source is connect-ed to any COM_ pin, it should be limited to the supply voltages. Exceeding the supply voltage will cause high currents to flow through the ESD protection diodes,possibly damaging the device (see Absolute Maximum Ratings ).Pin CompatibilityThese switches have identical pinouts to common non-fault-protected CMOS switches. Care should be exer-cised in considering them for direct replacements in existing printed circuit boards, however, since only the NO_ and NC_ pins of each switch are fault protected.Internal ConstructionInternal construction is shown in Figure 1, with the ana-log signal paths shown in bold. A single normally openFigure 1. Block DiagramM A X 4511/M A X 4512/M A X 4513Quad, Rail-to-Rail, Fault-Protected,SPST Analog Switches 10______________________________________________________________________________________(NO) switch is shown; the normally closed (NC) config-uration is identical except the logic-level translator becomes an inverter. The analog switch is formed by the parallel combination of N-channel FET N1 and P-channel FET P1, which are driven on and off simultane-ously according to the input fault condition and the logic-level state.Normal OperationTwo comparators continuously compare the voltage on the NO_ (or NC_) pin with V+ and V-. When the signal on NO_ or NC_ is between V+ and V- the switch acts normally, with FETs N1 and P1 turning on and off in response to IN_ signals. The parallel combination of N1 and P1 forms a low-value resistor between NO_ (or NC_) and COM_ so that signals pass equally well in either direction.Positive Fault ConditionWhen the signal on NO_ (or NC_) exceeds V+ by about 50mV, the high-fault comparator output is high, turning off FETs N1 and P1. This makes the NO_ (or NC_) pin high impedance regardless of the switch state. If the switch state is “off”, all FETs are turned off and both NO_ (or NC_) and COM_ are high impedance. If the switch state is “on”, FET P2 is turned on, sourcing cur-rent from V+ to COM_.Negative Fault ConditionWhen the signal on NO_ (or NC_) exceeds V- by about 50mV, the low-fault comparator output is high, turning off FETs N1 and P1. This makes the NO_ (or NC_) pin high impedance regardless of the switch state. If the switch state is “off,” all FETs are turned off and both NO_ (or NC_) and COM_ are high impedance. If the switch state is “on,” FET N2 is turned on, sinking cur-rent from COM_ to V-.Transient Fault Response and RecoveryWhen a fast rise-time and fall-time transient on IN_exceeds V+ or V-, the output (COM_) follows the input (IN_) to the supply rail with only a few nanoseconds delay. This delay is due to the switch on-resistance and circuit capacitance to ground. When the input transient returns to within the supply rails, however, there is a longer output recovery time delay. For positive faults, the recovery time is typically 3.5µs. For negative faults, the recovery time is typically 1.3µs. These values depend on the COM_ output resistance and capacitance, and are not production tested or guaranteed. The delays are not dependent on the fault amplitude. Higher COM_ output resistance and capacitance increase recovery times.COM_ and IN_ PinsFETs N2 and P2 can source about ±10mA from V+ or V-to the COM_ pin in the fault condition. Ensure that if the COM_ pin is connected to a low-resistance load, the absolute maximum current rating of 30mA is never exceeded, both in normal and fault conditions.The GND, COM_, and IN_ pins do not have fault protec-tion. Reverse ESD-protection diodes are internally con-nected between GND, COM_, IN_ and both V+ and V-. If a signal on GND, COM_, or IN_ exceeds V+ or V- by more than 300mV, one of these diodes will conduct heavily. During normal operation these reverse-biased ESD diodes leak a few nanoamps of current to V+ and V-.Fault-Protection Voltage and Power OffThe maximum fault voltage on the NC_ or NO_ pins is ±36V with power applied and ±40V with power off.Failure ModesThe MAX4511/MAX4512/MAX4513 are not lightning arrestors or surge protectors.Exceeding the fault-protection voltage limits on NO_ or NC_, even for very short periods, can cause the device to fail. The failure modes may not be obvious, and fail-ure in one switch may or may not affect other switches in the same package.GroundThere is no connection between the analog signal paths and GND. The analog signal paths consist of an N-channel and P-channel MOSFET with their sources and drains paralleled and their gates driven out of phase to V+ and V- by the logic-level translators.V+ and GND power the internal logic and logic-level translators and set the input logic thresholds. The logic-level translators convert the logic levels to switched V+and V- signals to drive the gates of the analog switch-es. This drive signal is the only connection between the power supplies and the analog signals. GND, IN_, and COM_ have ESD-protection diodes to V+ and V-.IN_ Logic-Level ThresholdsThe logic-level thresholds are CMOS and TTL compati-ble when V+ is +15V. As V+ is raised the threshold increases slightly, and when V+ reaches 25V the level threshold is about 2.8V—above the TTL output high level minimum of 2.4V, but still compatible with CMOS outputs (see Typical Operating Characteristics ).Increasing V- has no effect on the logic-level thresholds,but it does increase the gate-drive voltage to the signal FETs, reducing their on-resistance.MAX4511/MAX4512/MAX4513Quad, Rail-to-Rail, Fault-Protected,SPST Analog Switches______________________________________________________________________________________11Bipolar SuppliesThe MAX4511/MAX4512/MAX4513 operate with bipolar supplies between ±4.5V and ±18V. The V+ and V- sup-plies need not be symmetrical, but their difference can not exceed the absolute maximum rating of 44V.Single SupplyThe MAX4511/MAX4512/MAX4513 operate from a sin-gle supply between +9V and +36V when V- is connect-ed to GND.High-Frequency PerformanceIn 50Ωsystems, signal response is reasonably flat up to 50MHz (see Typical Operating Characteristics ). Above20MHz, the on-response has several minor peaks that are highly layout dependent. The problem with high-fre-quency operation is not turning the switch on, but turn-ing it off. The off-state switch acts like a capacitor and passes higher frequencies with less attenuation. At 10MHz, off isolation is about -42dB in 50Ωsystems,becoming worse (approximately 20dB per decade) as frequency increases. Higher circuit impedances also make off isolation worse. Adjacent channel attenuation is about 3dB above that of a bare IC socket and is due entirely to capacitive coupling.Figure 2. Switch Turn-On/Turn-Off TimesTest Circuits/Timing DiagramsFigure 3. MAX4513 Break-Before-Make IntervalM A X 4511/M A X 4512/M A X 4513Quad, Rail-to-Rail, Fault-Protected,SPST Analog Switches 12______________________________________________________________________________________Figure 4. Charge InjectionFigure 5. COM_, NO_, NC_ CapacitanceTest Circuits/Timing Diagrams (continued)MAX4511/MAX4512/MAX4513Quad, Rail-to-Rail, Fault-Protected,SPST Analog Switches______________________________________________________________________________________13Figure 6. Frequency Response, Off Isolation, and CrosstalkTest Circuits/Timing Diagrams (continued)Pin Configurations/Functional Diagrams/Truth Tables (continued)M A X 4511/M A X 4512/M A X 4513Quad, Rail-to-Rail, Fault-Protected,SPST Analog Switches 14______________________________________________________________________________________V-GNDNC4COM4IN4IN3COM30.086"(2.261mm)MAX4511NO1NO2COM1IN1IN2COM2COM4NO4IN4IN3NO3COM30.086"(2.261mm)MAX4512Ordering Information (continued)*Contact factory for dice specifications.Chip TopographiesV-GNDCOM4NO4IN4IN3NC3COM3MAX45130.086"(2.261mm)TRANSISTOR COUNT: 139SUBSTRATE CONNECTED TO:V+MAX4511/MAX4512/MAX4513Quad, Rail-to-Rail, Fault-Protected,SPST Analog Switches______________________________________________________________________________________15________________________________________________________Package InformationM A X 4511/M A X 4512/M A X 4513Quad, Rail-to-Rail, Fault-Protected,SPST Analog Switches Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.16____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600©1998 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.Package Information (continued)。

max485esa中文资料

General DescriptionThe MAX481, MAX483, MAX485, MAX487–MAX491, andMAX1487 are low-power transceivers for RS-485 and RS-422 communication. Each part contains one driver and onereceiver. The MAX483, MAX487, MAX488, and MAX489feature reduced slew-rate drivers that minimize E MI andreduce reflections caused by improperly terminated cables,thus allowing error-free data transmission up to 250kbps.The driver slew rates of the MAX481, MAX485, MAX490,MAX491, and MAX1487 are not limited, allowing them totransmit up to 2.5Mbps.These transceivers draw between 120µA and 500µA ofsupply current when unloaded or fully loaded with disableddrivers. Additionally, the MAX481, MAX483, and MAX487have a low-current shutdown mode in which they consumeonly 0.1µA. All parts operate from a single 5V supply.Drivers are short-circuit current limited and are protectedagainst excessive power dissipation by thermal shutdowncircuitry that places the driver outputs into a high-imped-ance state. The receiver input has a fail-safe feature thatguarantees a logic-high output if the input is open circuit.The MAX487 and MAX1487 feature quarter-unit-loadreceiver input impedance, allowing up to 128 MAX487/MAX1487 transceivers on the bus. Full-duplex communi-cations are obtained using the MAX488–MAX491, whilethe MAX481, MAX483, MAX485, MAX487, and MAX1487are designed for half-duplex applications.________________________Applications Low-Power RS-485 Transceivers Low-Power RS-422 Transceivers Level Translators Transceivers for EMI-Sensitive Applications Industrial-Control Local Area Networks__Next Generation Device Features o For Fault-Tolerant Applications MAX3430: ±80V Fault-Protected, Fail-Safe, 1/4Unit Load, +3.3V, RS-485 Transceiver MAX3440E–MAX3444E: ±15kV ESD-Protected,±60V Fault-Protected, 10Mbps, Fail-Safe, RS-485/J1708 Transceivers o For Space-Constrained Applications MAX3460–MAX3464: +5V, Fail-Safe, 20Mbps,Profibus RS-485/RS-422 Transceivers MAX3362: +3.3V, High-Speed, RS-485/RS-422Transceiver in a SOT23 Package MAX3280E–MAX3284E: ±15kV ESD-Protected,52Mbps, +3V to +5.5V, SOT23, RS-485/RS-422,True Fail-Safe Receivers MAX3293/MAX3294/MAX3295: 20Mbps, +3.3V,SOT23, RS-485/RS-422 Transmitters o For Multiple Transceiver Applications MAX3030E–MAX3033E: ±15kV ESD-Protected,+3.3V, Quad RS-422 Transmitters o For Fail-Safe Applications MAX3080–MAX3089: Fail-Safe, High-Speed (10Mbps), Slew-Rate-Limited RS-485/RS-422Transceiverso For Low-Voltage ApplicationsMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E: +3.3V Powered, ±15kVESD-Protected, 12Mbps, Slew-Rate-Limited,True RS-485/RS-422 Transceivers For pricing, delivery, and ordering information, please contact Maxim Direct at1-888-629-4642, or visit Maxim Integrated’s website at .______________________________________________________________Selection Table19-0122; Rev 10; 9/14PARTNUMBERHALF/FULL DUPLEX DATA RATE (Mbps) SLEW-RATE LIMITED LOW-POWER SHUTDOWN RECEIVER/DRIVER ENABLE QUIESCENT CURRENT (μA) NUMBER OF RECEIVERS ON BUS PIN COUNT MAX481Half 2.5No Yes Yes 300328MAX483Half 0.25Yes Yes Yes 120328MAX485Half 2.5No No Yes 300328MAX487Half 0.25Yes Yes Yes 1201288MAX488Full 0.25Yes No No 120328MAX489Full 0.25Yes No Yes 1203214MAX490Full 2.5No No No 300328MAX491Full 2.5No No Yes 3003214MAX1487 Half 2.5No No Yes 2301288Ordering Information appears at end of data sheet.找电子元器件上宇航军工MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-LimitedRS-485/RS-422 TransceiversPackage Information For the latest package outline information and land patterns, go to . Note that a “+”, “#”, or “-”in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status.16Low-Power, Slew-Rate-Limited RS-485/RS-422 TransceiversMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-100017©2014 Maxim Integrated Products, Inc.Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.。

MX4054 充电IC

General DescriptionThe MX4054 is a complete constant-current/constant- voltage linear charger for single cell lithium-ion batteries. Its ThinSOT package and low external component count make the MX4054 ideally suited for portable applications. Furthermore, the MX4054 is specifically designed to work within USB power specifications.No external sense resistor is needed, and no blocking diode is required due to the internal MOSFET architecture. Thermal feedback regulates the charge current to limit the die temperature during high power operation or high ambient temperature. The charge voltage is fixed at 4.2V, and the charge current can be programmed externally with a single resistor. The MX4054 automatically terminates the charge cycle when the charge current drops to 1/10th the programmed value after the final float voltage is reached. When the input supply (wall adapter or USB supply) is removed, the MX4054 automatically ent e rs a low current state, dropping the battery drain current to less than 2µA. The MX4054 can be put into shut d own mode, reducing he supply current to 25µA.Other features include charge current monitor, undervoltage lockout, automatic recharge and a status pin to indicate charge termination and the presence of an input voltage.Ordering Information□ □ □Package B5:SOT23-5FeaturesProgrammable Charge Current Up to 800mA No MOSFET, Sense Resistor or Blocking DiodeRequiredComplete Linear Charger in ThinSOTPackage forSingle Cell Lithium-ion BatteriesConstant-Current/Constant-Voltage Operationwith Thermal Regulation to Maximize Charge Rate Without Risk of OverheatingCharges Single Cell Li-Ion Batteries Directlyfrom USB PortPreset 4.2V Charge Voltage with ± 1% Accuracy Charge Current Monitor Output for GasGaugingAutomatic RechargeSoft-Start Limits Inrush CurrentAvailable in 5-Lead SOT-23 Package 2.9V Trickle Charge Threshold C/10 Charge Termination25mA Supply Current in Shutdown 2.9V Trickle Charge ThresholdApplicationsPortable Media Players/MP3 players Cellular and Smart mobile phone Charging Docks and Cradles Bluetooth ApplicationsMarking InformationPlease see website.F:PB-Free MX4054Standalone Linear Li-Ion Battery ChargerWith Thermal Regulation in ThinSOTTypical Application CircuitMX4054MX4054MX4054MX4054MX4054Functional Pin DescriptionPINDESCRIPTIONCHRG 1 Open-Drain Status OutputGND 2GroundBAT 3 Charge Current Output VCC4Positive Input Supply VoltagePROG 5Charge Current Program, Charge Current Monitor andShutdown Pin.Pin FunctionsCHRG (PIN 1):Open-Drain Charge Status Output. When the battery is charging, the CHRG pin is pulled low by an internal N-channel MOSFET. When the charge cycle is completed, a weak pull-down of approximately 12µA is connected to the CHRG pin, indicating a “AC present” condition. When the MX4054 detects an undervoltage lockout condition, CHRG is forced high impedance.GND (PIN 2): Ground. BAT (PIN 3):Charge Current Output. Provides charge current to the battery and regulates the final float voltage to 4.2V. An internal precision resistor divider from this pin sets the float voltage which is disconnected in shutdown mode. VCC (PIN 4): Positive Input Supply Voltage. Provides power to the charger. V CC can range from 4.35V to 6.5V and should be bypassed with at least a 1µF capacitor. When V CC drops to within 30mV of the BAT pin voltage, the MX4054 enters shutdown mode, dropping IBAT to less than 2µA.PROG (PIN 5): Charge Current Program, Charge Current Monitor and Shutdown Pin. The charge current is programmed by connecting a 1% resistor, R PROG , to ground. When charging in constant-current mode, this pin servos to 1V. In all modes, the voltage on this pin can be used to measure the charge current using the following formula:The PROG pin can also be used to shutdown the charger. Disconnecting the program resistor from ground allows a 3µA current to pull the PROG pin high. When it reaches the 1.94V shutdown threshold voltage, the charger enters shutdown mode, charging stops and the input supply current drops to 25µA. This pin is also clamped to approximately 2.4V. Driving this pin to voltages beyond the clamp voltage will draw currents as high as1.5mA. Reconnecting R PROG to ground will return the charger to normal operation.MX4054TSOT-23-5MX4054Function Block DiagramAbsolute Maximum RatingsElectrical Characteristics (Over 0C ≤TJ ≤125°C and recommended supply voltage)Note 1: Absolute Maximum Ratings are those values beyond which the life of the device may be impaired.Note 2: The MX4054 are guaranteed to meet performance specifications from 0℃ to 70℃. Specifications over the -40℃ to 85℃ operating temperature range are assured by design, characterization and correlation with statistical process controls.Note 3: See Thermal Considerations.Note 4: Supply current includes PROG pin current (approximately 100µA) but does not include any current delivered to the battery through the BAT pin (approximately 100mA).Note 5: This parameter is not applicable to the MX4054.Note 6: I TERM is expressed as a fraction of measured full charge current with indicated PROG resistor.Typical Operating CharacteristicsOperationThe MX4054 is a single cell lithium-ion battery charger using a constant-current/constant-voltage algorithm. It can deliver up to 800mA of charge current (using a good thermal PCB layout) with a final float voltage accuracy of ± 1%. The MX4054 includes an internal P-channel power MOSFET and thermal regulation circuitry. No blocking diode or external current sense resistor is required; thus, the basic charger circuit requires only two external components. Furthermore, the MX4054 is capable of operating from a USB power source.Normal Charge CycleA charge cycle begins when the voltage at the V CC pin rises above the UVLO threshold level and a 1% program resistor is connected from the PROG pin to ground or when a battery is connected to the charger output. If the BAT pin is less than 2.9V, the charger enters trickle charge mode. In this mode, the MX4054 supplies approximately 1/10 the programmed charge current to bring the battery voltage up to a safe level for full current charging. (Note: The MX4054 does not include this trickle charge feature).When the BAT pin voltage rises above 2.9V, the charger enters constant-current mode, where the programmed charge current is supplied to the battery. When the BAT pin approaches the final float voltage (4.2V), the MX4054 enters constant-voltage mode and the charge current begins to decrease. When the charge current drops to 1/10 of the programmed value, the charge cycle ends.Programming Charge CurrentThe charge current is programmed using a single resistor from the PROG pin to ground. The battery charge current is 1000 times the current out of the PROG pin. The program resistor and the charge current are calculated using the following equations:The charge current out of the BAT pin can be determined at any time by monitoring the PROG pin voltage using the following equation:Charge TerminationA charge cycle is terminated when the charge current falls to 1/10th the programmed value after the final float voltage is reached. This condition is detected by using an internal, filtered comparator to monitor the PROG pin. When the PROG pin voltage falls below 100mV for longer than tTERM (typically 1ms), charging is terminated. The charge current is latched off and the MX4054 enters standby mode, where the input supply current drops to 200µA.When charging, transient loads on the BAT pin can cause the PROG pin to fall below 100mV for short periods of time before the DC charge current has dropped to 1/10th the programmed value. The 1ms filter time (T TERM) on the termination comparator ensures that transient loads of this nature do not result in premature charge cycle termination. Once the average charge current drops below 1/10th the programmed value, the MX4054 terminates the charge cycle and ceases to provide any current through the BAT pin. In this state, all loads on the BAT pin must be supplied by the battery.The MX4054 constantly monitors the BAT pin voltage in standby mode. If this voltage drops below the 4.05V recharge threshold (V RECHRG), another charge cycle begins and current is once again supplied to the battery. To manually restart a charge cycle when in standby mode, the input voltage must be removed and reapplied, or the charger must be shut down and restarted using the PROG pin. Figure 7 shows the state diagram of a typical charge cycle.Charge Status Indicator(CHRG)The charge status output has three different states: strong pull-down(~10mA), weak pull-down (~12µA) and high impedance. The strong pull-down state indicates that the MX4054 is in a charge cycle. Once the charge cycle has terminated , the pin state is determined by undervoltage lockout conditions. A weak pull-down indicates that V CC meets the UVLO conditions and the MX4054 is ready to charge.High impedance indicates that the MX4054 is in undervoltage lockout mode: either V CC is less than 100mV above the BAT pin voltage or insufficient voltage is applied to the V CC pin. Amicroprocessor can be used to distinguish betweenthese three states –this method is discussed in the Applications Information section.Charge TerminationAn internal thermal feedback loop reduces the programmed charge current if the die temperature attempts to rise above a preset value of approximately 120℃. This feature protects the MX4054 from excessive temperature and allows the user to push the limits of the power handling capability of a given circuit board without risk of damaging the MX4054. The charge current can be set according to typical (not worst-case) ambient temperature with the assurance that the charger will automatically reduce the current in worst-case conditions. ThinSOT power considerations are discussed further in the Applications Information section.Undervoltage Lockout (UVLO)An internal undervoltage lockout circuit monitors the input voltage and keeps the charger in shutdown mode until V CC rises above the undervoltage lockout threshold .The UVLO circuit has a built-in hysteresis of 200mV. Furthermore, to protect against reverse current in the power MOSFET, the UVLO circuit keeps the charger in shutdown mode if V CC falls to within 30mV of the battery voltage. If the UVLO comparator is tripped, the charger will not come out of shutdown mode until V CC rises 100mV above the battery voltage.Manual ShutdownAt any point in the charge cycle, the MX4054 can be put into shutdown mode by removing RPROG thus floating the PROG pin. This reduces the battery drain current to less than 2µA and the supply current to less than 50µA. A new charge cycle can be initiated by reconnecting the program resistor. In manual shutdown, the CHRG pin is in a weakpull-down state as long as VCC is high enough to exceed the UVLO conditions. The CHRG pin is in a high impedance state if the MX4054 is in under voltage lockout mode: either VCC is within 100mV of the BAT pin voltage or insufficient voltage is applied to the VCC pin.Automatic RechargeOnce the charge cycle is terminated, the MX4054 continuously monitors the voltage on the BAT pin using a comparator with a 2ms filter time (T RECHARGE). A charge cycle restarts when the battery voltage falls below 4.05V (which corresponds to approximately 80% to 90% battery capacity). This ensures that the battery is kept at or near a fully charged condition and eliminates the need for periodic charge cycle initiations. CHRG output enters a strong pull-down state duringrecharge cycles.Application InformationStability ConsiderationsThe constant-voltage mode feedback loop is stable without an output capacitor provided a battery is connected to the charger output. With no battery present, an output capacitor is recommended to reduce ripple voltage. When using high value, low ESR ceramic capacitors, it is recommended to add a 1Ω resistor in series with the capacitor. No series resistor is needed if tantalum capacitors are used. In constant-current mode, the PROG pin is in the feedback loop, not the battery. The constant-current mode stability is affected by the impedance at the PROG pin. With no additional capacitance on the PROG pin, the charger is stable withprogram resistor values as high as 20k. However,additional capacitance on this node reduces the maximum allowed program resistor. The pole frequency at the PROG pin should be kept above 100kHz. Therefore, if the PROG pin is loaded with a capacitance, PROG, the following equation can be used to calculatethe maximum resistance value for RPROG:Average, rather than instantaneous, charge current may be of interest to the user. For example, if a switching power supply operating in low current mode is connected in parallel with the battery, the average current being pulled out of the BAT pin is typically of more interest than the instantaneous current pulses. In such a case, a simple RC filter can be used on the PROG pin to measure the average battery current as shown in Figure 8. A 10k resistor has been added between the PROG pin and the filter capacitor to ensurestability.Power DissipationThe conditions that cause the MX 4054 to reduce chargecurrent through thermal feedback can be approximated byconsidering the power dissipated in the IC. Nearly all of thispower dissipation is generated by the internalMOSFET—this is calculated to be approximately:P D =(V CC －V BAT ) • I BATwhere P D is the power dissipated, V CC is the input supply voltage, V BAT is the battery voltage and I BAT is the charge current. The approximate ambient temperature at which the thermal feedback begins to protect the IC is:T A =120℃-P D θJAT A =120℃-(V CC -V BAT ) • I BAT • θJAExample: An MX4054 operating from a 5V USB supply is programmed to supply 400mA full-scale current to a discharged Li-Ion battery with a voltage of 3.75V. Assuming θJA is 150℃/W (see Board Layout Considerations ), the ambient temperature at which the MDX4054 will begin to reduce the charge current is approximately:T A =120℃-(5V-3.75V) • (400mA) • 150℃/W T A =120℃-0.5W • 150℃/W =120℃-75℃ T A =45℃The MX 4054 can be used above 45℃ ambient, but the charge current will be reduced from 400mA. Theapproximate current at a given ambient temperature can be approximated by:Using the previous example with an ambient temperature of 60℃, the charge current will be reducedto approximately:Moreover, when thermal feedback reduces the chargecurrent, the voltage at the PROG pin is also reducedproportionally as discussed in the Operation section. Itis important to remember that MX4054 applications donot need to be designed for worst-case thermalconditions since the IC will automatically reduce powerdissipation when the junction temperature reaches approximately 120℃.Thermal Considerations Because of the small size of the ThinSOTpackage, it is very important to use a good thermal PC board layout to maximize the available charge current. The thermal path for the heat generated by the IC is from the die to the copper lead frame, through the package leads, (especially the ground lead) to the PC board copper. The PC board copper is the heat sink. The footprint copper pads should be as wide asFigure 8. Isolating Capacitive Load on PROG Pin and Filteringpossible and expand out to larger copper areas to spread and dissipate the heat to the surrounding ambient. Feedthrough vias to inner or backside copper layers are also useful in improving the overall thermal performance of the charger .Other heat sources on the board, not related to the charger , must also be considered when designing a PC board layout because they will affect overall temperature rise and the maximum charge current.Increasing Thermal Regulation CurrentReducing the voltage drop across the internal MOSFET can significantly decrease the power dissipation in the IC. This has the effect of increasing the current delivered to the battery during thermal regulation.One method is by dissipating some of the power through an external component, such as a resistor or diode.Example: An MX4054 operating from a 5V wall adapter is programmed to supply 800mA full-scale current to a discharged Li-Ion battery with a voltage of 3.75V. Assuming θJA is 125℃/W, the approximate charge current at an ambient temperature of 25℃ is:By dropping voltage across a resistor in series with a 5V wall adapter (shown in Figure 9), the on-chip power dissipation can be decreased, thus increasing thethermally regulated charge current.:Solving for I BAT using the quadratic formaula 2Using R CC = 0.25Ω, V S = 5V, V BAT = 3.75V, T A = 25℃ and θJA = 125℃/W we can calculate the thermally regulated charge current to be:While this application delivers more energy to the battery and reduces charge time in thermal mode, it may actually lengthen charge time in voltage mode if VCC becomes low enough to put the MX4054 into dropout.This technique works best when RCC values are minimized to keep component size small and avoid dropout. Remember to choose a resistor with adequate power handling capability.VCC Bypass CapacitorMany types of capacitors can be used for input bypassing, however, caution must be exercised when using multilayer ceramic capacitors. Because of the self-resonant and high Q characteristics of some types of ceramic capacitors, high voltage transients can be generated under some start-up conditions, such as connecting the charger input to a live power source .Adding a 1.5Ω resistor in series with an X5Rceramic capacitor will minimize start-up voltageMX4054transients.Charge Current Soft-StartThe MX4054 includes a soft-start circuit to minimize the inrush current at the start of a charge cycle. When acharge cycle is initiated, the charge current ramps fromzero to the full-scale current over a period of approximately 100µs. This has the effect of minimizingthe transient current load on the power supply duringstart-up.CHRG Status Output PinThe CHRG pin can provide an indication that the input voltage is greater than the undervoltage lockout threshold level. A weak pull-down current of approximately 12µA indicates that sufficient voltage is applied to VCC to begin charging. When a discharged battery is connected to the charger, the constant current portion of the charge cycle begins and the CHRG pin pulls to ground. The CHRG pin can sink up to 10mA to drive an LED that indicates that a charge cycle is in progress. When the battery is nearing full charge, the charger enters the constant-voltage portion of the charge cycle and the charge current begins to drop. When the charge current drops below 1/10 of the programmed current, the charge cycle ends and the strong pull-down is replaced by the 12µA pull-down, indicating that the charge cycle has ended. If the input voltage is removed or drops below the under voltagelockout threshold, the CHRG pin becomes high impedance. Figure 10 shows that by using two different value pull-up resistors, amicro-processor can detect all three states fromthis pin.To detect when the MX4054 is in charge mode, force the digital output pin (OUT) high and measure the voltage at the CHRG pin. The N-channel MOSFET will pull thepin voltage low even with the 2k pull-up resistor. Once the charge cycle terminates, the N-channel MOSFET is turned off and a 12µA current source is connected tothe CHRG pin. The IN pin will then be pulled high by the 2k pull-up resistor. To determine if there is a weak pull-down current, the OUT pin should be forced to ahigh impedance state. The weak current source will pull the IN pin low through the 800k resistor; if CHRG is high impedance, the IN pin will be pulled high, indicating that the part is in a UVLO state. Reverse Polarity Input Voltage ProtectionIn some applications, protection from reverse polarity voltage on VCC is desired .If the supply voltage is high enough, a series blocking diode can be used. In other cases, where the voltage drop must be kept low a P-channel MOSFET can be used (as shown in Fig 11.)USB and Wall Adapter Power The MX4054 allows charging from both a wall adapter and a USB port. Figure 12 shows an example of how to combine wall adapter and USB power inputs. AP-channel MOSFET, MP1,is used to prevent back conducting into the USB port when a wall adapter is present and a Schottky diode, D1, is used to preventUSB power loss through the 1k pull-down resistor. Typically a wall adapter can supply more current thanthe 500mA-limited USB port. Therefore, an N-channel MOSFET, MN1, and extra 10k program resistor are used to increase the charge current to 600mA when the wall adapter is present.Packaging Information。

MAX3841中文资料

PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX UNITS
Core Supply Current Data Rate
ICC
Excluding CML termination currents
(Note 1)
65
90
mA
0
12.5 Gbps
CML Input Differential CML Input Common Mode
Termination Currents)
Ordering Information
PART
TEMP RANGE
MAX3841ETG -40°C to +85°C
PINPACKAGE
24 Thin QFN
PKG. CODE
T2444-1
Pin Configuration appears at end of data sheet.
12
dB
CML Output Differential CML Output Termination
VOUT
(Note 2) Single ended
400
500
42.5
50
600 57.5
mVP-P Ω
CML Output Transition Time Deterministic Jitter Random Jitter Propagation Delay
Note 4: Measured at 9.953Gbps using a pattern of 100 ones, 27 - 1 PRBS, 100 zeros, 27 - 1 PRBS, and at 12.5Gbps using a ±K28.5 pattern. VCC_IN = VCC_OUT = 1.8V, and VIN = 400mVP-P differential.

CD4051中文资料(管脚,功能,参数使用介绍)之欧阳体创编

CD4051中文资料(管脚,功能,参数使用介绍)CD4051中文资料(管脚,功能,参数使用介绍)CD4051功能及使用概述:CD4051相当于一个单刀八掷开关，开关接通哪一通道，由输入的3位地址码ABC来决定。

INH”是禁止端，当“INH”=1时，各通道均不接通。

此外，CD4051还设有另外一个电源端VEE，以作为电平位移时使用，从而使得通常在单组电源供电条件下工作的 CMOS电路所提供的数字信号能直接控制这种多路开关，并使这种多路开关可传输峰－峰值达15V的交流信号。

例如，若模拟开关的供电电源VDD=＋5V，VSS=0V，当VEE=－5V时，只要对此模拟开关施加0～5V的数字控制信号，就可控制幅度范围为－5V～＋5V的模拟信号。

. 使用十六进制代码就可以对CD4051进行操作了。

比如说P1=0X07，这样CD4051就选择的是7号（二进制111）通道了。

如果在八个通道输入一模拟量，在输出端将输出什么,输入什么是自己设定例如，若模拟开关的供电电源VDD=＋5V，VSS=0V，只要对此模拟开关施加0～5V的数字控制信号，...这里,ABC数字控制信号就可以使用5V信号了,因为VDD是5v,里面控制部分就都是5V逻辑.当VEE=－5V时，就可控制幅度范围为－5V～＋5V的模拟信号。

当Vee=-8V时,就可以可控制幅度范围为－8V～＋5V的模拟信号.Vee就是电子开关的8个输入端可以允许的信号范围下限.注意不要超过它的极限参数.峰－峰值达15VCD4051管脚图及逻辑符号图引脚功能描述：A0～A2 地址端I0/O0～I7/O7 输入输出端INH 禁止端O/I 公共输出/输入端VDD 正电源VEE 模拟信号地Vss 数字信号地CD4051逻辑图与真值表CD4051参数电源电压范围…………3V～15V输入电压范围…………0V～VDD工作温度范围M类…………－55℃～125℃E 类………….－40℃～85℃极限值：电源电压…...－0.5V～18V输入电压……－0.5V~VDD+0.5V输入电流…………….±10mA储存温度…………－65℃～150℃。

MAX4051ACSE+中文资料

VCOM = ±3V
MAX4051, TA = +25°C
12
MAX4052,
MAX4053 C, E, M
MAX4051ACPE来自0°C to +70°C 16 Plastic DIP
MAX4051ACSE
0°C to +70°C 16 Narrow SO
MAX4051ACEE
0°C to +70°C 16 QSOP
Ordering Information continued at end of data sheet.
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at .
元器件交易网
Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C
Note 1: Signals on any terminal exceeding V+ or V- are clamped by internal diodes. Limit forward-diode current to maximum current rating.
Continuous Power Dissipation (TA = +70°C) Plastic DIP (derate 10.53mW/°C above +70°C)............842mW Narrow SO (derate 8.70mW/°C above +70°C)..............696mW QSOP (derate 8.00mW/°C above +70°C) .....................640mW CERDIP (derate 10.00mW/°C above +70°C) ................800mW

MEMORY存储芯片MAX4053ESE+T中文规格书

Figure 8. Driver Propagation TimesFigure 9. Driver Enable and Disable Times (t PZH , t PSH , t PHZ )Figure 10. Driver Enable and Disable Times (t PZL , t PSL , t PLZ )MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited True RS-485/RS-422 TransceiversDriver Output ProtectionExcessive output current and power dissipation caused by faults or by bus contention are prevented by two mechanisms. A foldback current limit on the output stage provides immediate protection against short circuits over the whole common-mode voltage range (see Typical Operating Characteristics ). In addition, a thermal shut-down circuit forces the driver outputs into a high-imped-ance state if the die temperature rises excessively.Propagation DelayFigures 15–18 show the typical propagation delays. Skew time is simply the difference between the low-to-high and high-to-low propagation delay. Small driver/receiver skew times help maintain a symmetrical mark-space ratio (50% duty cycle).The receiver skew time, |tPRLH - t PRHL |, is under 10ns 20ns for the MAX3483E/MAX3488E). The driver skew times are 8ns for the MAX3485E/MAX3490E/MAX3491E, 12ns for the MAX3486E, and typically under 50ns for the MAX3483E/MAX3488E.Line Length vs. Data RateThe RS-485/RS-422 standard covers line lengths up to 4000 feet. For line lengths greater than 4000 feet, see Figure 21 for an example of a line repeater.Figures 19 and 20 show the system differential voltage for parts driving 4000 feet of 26AWG twisted-pair wire at 125kHz into 120Ω loads.For faster data rate transmission, please consult the factory.±15kV ESD Protection As with all Maxim devices, ESD-protection structures are incorporated on all pins to protect against electrostatic discharges encountered during handling and assembly. The driver outputs and receiver inputs of the MAX3483E family of devices have extra protection against static electricity. Maxim’s engineers have developed state-of-the-art structures to protect these pins against ESD of ±15kV without damage. The ESD structures withstand high ESD in all states: normal operation, shutdown, and powered down. After an ESD event, Maxim’s E versions keep working without latchup or damage.ESD protection can be tested in various ways; the trans-mitter outputs and receiver inputs of this product family are characterized for protection to the following limits:1)±15kV using the Human Body Model 2)±8kV using the Contact-Discharge method specified in IEC 1000-4-23)±15kV using IEC 1000-4-2’s Air-Gap method.ESD Test Conditions ESD performance depends on a variety of conditions. Contact Maxim for a reliability report that documents test setup, test methodology, and test results.Human Body Model Figure 22a shows the Human Body Model and Figure 22b shows the current waveform it generates when dis-charged into a low impedance. This model consists of a 100pF capacitor charged to the ESD voltage of interest, which is then discharged into the test device through a 1.5kΩ resistor.IEC 1000-4-2The IEC 1000-4-2 standard covers ESD testing and performance of finished equipment; it does not specifi-cally refer to integrated circuits. The MAX3483E family of devices helps you design equipment that meets Level 4 (the highest level) of IEC 1000-4-2, without the need for additional ESD-protection components.The major difference between tests done using the Human Body Model and IEC 1000-4-2 is higher peak cur-rent in IEC 1000-4-2, because series resistance is lower in the IEC 1000-4-2 model. Hence, the ESD withstand voltage measured to IEC 1000-4-2 is generally lower than that measured using the Human Body Model. Figure 23a shows the IEC 1000-4-2 model, and Figure 23b shows the current waveform for the ±8kV IEC 1000-4-2, Level 4ESD contact-discharge test. test.Figure 21. Line Repeater for MAX3488E/MAX3490E/MAX3491EMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers。

MAXIM MAX4561 MAX4568 MAX4569 数据手册

General DescriptionThe MAX4561/MAX4568/MAX4569 are low-voltage,ESD-protected analog switches. The normally open (NO) and normally closed (NC) inputs are protected against ±15kV electrostatic discharge (ESD) without latchup or damage, and the COM input is protected against 2.5kV ESD.These switches operate from a single +1.8V to +12V supply. The 70Ωat 5V (120Ωat 3V) on-resistance is matched between channels to 2Ωmax, and is flat (4Ωmax) over the specified signal range. The switches can handle Rail-to-Rail ® analog signals. Off-leakage current is only 0.5nA at +25°C and 5nA at +85°C. The digital input has +0.8V to +2.4V logic thresholds, ensuring TTL/CMOS-logic compatibility when using a single +5V supply. The MAX4561 is a single-pole/double-throw (SPDT) switch. The MAX4568 NO and MAX4569 NC are single-pole/single-throw (SPST) switches.The MAX4561 is available in a 6-pin SOT23 package,and the MAX4568/MAX4569 are available in 5-pin SOT23 packages.________________________ApplicationsHigh-ESD Environments Battery-Powered Systems Audio and Video Signal Routing Low-Voltage Data-Acquisition Systems Sample-and-Hold Circuits Communications CircuitsFeatureso ESD-Protected NO, NC±15kV—Human Body Model±15kV—IEC 1000-4-2, Air-Gap Discharge ±8kV—IEC 1000-4-2, Contact Discharge o Guaranteed On-Resistance70Ω+5V Supply120Ωwith Single +3V Supplyo On-Resistance Match Between Channels (2Ωmax)o Low On-Resistance Flatness: 4Ωmax o Guaranteed Low Leakage Currents0.5nA Off-Leakage (at T A = +25°C)0.5nA On-Leakage (at T A = +25°C)o Guaranteed Break-Before-Make at 5ns(MAX4561 only)o Rail-to-Rail Signal Handling Capabilityo TTL/CMOS-Logic Compatible with +5V Supplies o Industry Standard Pin-OutsMAX4561 Pin Compatible with MAX4544MAX4568/MAX4569 Pin Compatible with MAX4514/MAX4515MAX4561/MAX4568/MAX4569±15kV ESD-Protected, Low-Voltage,SPDT/SPST, CMOS Analog Switches________________________________________________________________Maxim Integrated Products 1Pin Configurations/Functional Diagrams/Truth Tables19-1714; Rev 0; 4/00For free samples and the latest literature, visit or phone 1-800-998-8800.For small orders, phone 1-800-835-8769.Ordering InformationRail-to-Rail is a registered trademark of Nippon Motorola, Ltd.查询MAX4561EUT-T供应商M A X 4561/M A X 4568/M A X 4569±15kV ESD-Protected, Low-Voltage,SPDT/SPST, CMOS Analog Switches 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICS —Single +5V Supply(V+ = +4.5V to +5.5V, V IH = +2.4V, V IL = +0.8V, T A = T MIN to T MAX , unless otherwise specified. Typical values are at T A = +25°C.)Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.V+ to GND................................................................-0.3 to +13V IN, COM, NO, NC to GND (Note 1)..............-0.3V to (V+ + 0.3V)Continuous Current (any terminal)....................................±10mA Peak Current(NO, NC, COM; pulsed at 1ms 10% duty cycle).........±30mA ESD Protection per Method IEC 1000-4-2 (NO, NC)Air-Gap Discharge........................................................±15kV Contact Discharge..........................................................±8kVESD Protection per Method 3015.7V+, GND, IN, COM.......................................................±2.5kV NO, NC..........................................................................±15kV Continuous Power Dissipation (T A = +70°C)SOT23 (derate 8.7mW/°C above +70°C)....................696mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10s).................................+300°CNote 1:Signals on NO, NC, COM, or IN exceeding V+ or GND are clamped by internal diodes. Limit forward current to maximumcurrent rating.MAX4561/MAX4568/MAX4569±15kV ESD-Protected, Low-Voltage,SPDT/SPST, CMOS Analog Switches_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS —Single +5V Supply (continued)050150100200250ON-RESISTANCEvs. V COM AND SUPPLY VOLTAGEV COM (V)R O N (Ω)4812302010405060021345ON-RESISTANCE vs. TEMPERATUREV COM (V)R D S (O N ) (Ω)40020010008006001600140012001800-4020-20406080100LEAKAGE CURRENT vs. TEMPERATURETEMPERATURE (°C)L E A K A G E C U R R E N T (p A )Typical Operating Characteristics(T A = +25°C, unless otherwise noted.)M A X 4561/M A X 4568/M A X 4569±15kV ESD-Protected, Low-Voltage,SPDT/SPST, CMOS Analog Switches 4_______________________________________________________________________________________ELECTRICAL CHARACTERISTICS —Single +3V Supply(V+ = +2.7V to +3.6V, V IH = +2.0V, V IL = +0.6V, T A = T MIN to T MAX , unless otherwise specified. Typical values are at T A = +25°C.)Note 3:Parameters are 100% tested at +25°C and guaranteed by correlation at the full rated temperature.Note 4:∆R ON = R ON(MAX)- R ON(MIN).Note 5:Flatness is defined as the difference between the maximum and the minimum value of on-resistance as measured over thespecified analog signal ranges.Note 6:Off-Isolation = 20log 10(V COM /V NO ), V COM = output, V NO = input to off switch.MAX4561/MAX4568/MAX4569±15kV ESD-Protected, Low-Voltage,SPDT/SPST, CMOS Analog Switches________________________________________________________________________________________50201040305060-402040-206080100SUPPLY CURRENTvs. TEMPERATURE AND SUPPLY VOLTAGETEMPERATURE (°C)S U P P L Y C U R R E N T (n A)40208060100120-40020-20406080TURN-ON/TURN-OFF TIME vs. TEMPERATURETEMPERATURE (°C)t O N /t O F F (n s )40208060100120021345TURN-ON/TURN-OFF TIME vs. V COMV COM (V)t O N /t O F F (n s )TURN-ON/TURN-OFF TIME vs. V COM02040608010012014016001.00.51.52.02.53.0V COM (V)t O N /t O F F (n s )010050200150300250350TURN-ON/TURN-OFF TIME vs. SUPPLY VOLTAGESUPPLY VOLTAGE (V)t O N /t O F F (n s )12345Typical Operating Characteristics (continued)(T A = +25°C, unless otherwise noted.)40208060120100140180160200-60-20-4020406080100SCR HOLDING CURRENT vs. TEMPERATURETEMPERATURE (°C)H O L D I N G C U R R E N T (m A )-40-25-30-35-20-15-10-5051021345MAX4561CHARGE INJECTION vs. V COMV COM (V)Q (p C)-1050-5101520021345MAX4568/MAX4569CHARGE INJECTION vs. V COMV COM (V)Q (p C )M A X 4561/M A X 4568/M A X 4569±15kV ESD-Protected, Low-Voltage,SPDT/SPST, CMOS Analog Switches 6_______________________________________________________________________________________Do not exceed the absolute maximum ratings because stresses beyond the listed ratings may cause perma-nent damage to the device.Proper power-supply sequencing is recommended for all CMOS devices. Always sequence V+ on first, fol-lowed by the logic inputs, NO/NC, or COM.High-Voltage SupplyThe MAX4561/MAX4568/MAX4569 are capable of +12V single-supply operation with some precautions.The absolute maximum rating for V+ is +13V (refer-enced to GND). When operating near this region,bypass V+ with a 0.1µF min capacitor to ground as close to the device as possible.Typical Operating Characteristics (continued)(T A = +25°C, unless otherwise noted.)10100010010,000100,000TOTAL HARMONIC DISTORTIONvs. FREQUENCYFREQUENCY (Hz)T H D (%)10.0010.010.10.010.11001000FREQUENCY RESPONSEFREQUENCY (MHz)L O S S (d B )20-100-80-60-40-200110MAX4561/MAX4568/MAX4569±15kV ESD-Protected, Low-Voltage,SPDT/SPST, CMOS Analog Switches_______________________________________________________________________________________7±15kV ESD ProtectionThe MAX4561/MAX4568/MAX4569 are ±15kV ESD-pro-tected at the NC/NO terminals in accordance with IEC1000-4-2. To accomplish this, bidirectional SCRs are included on-chip between these terminals. When the voltages at these terminals go Beyond-the-Rails ™,the corresponding SCR turns on in a few nanoseconds and bypasses the surge safely to ground. This method is superior to using diode clamps to the supplies because unless the supplies are very carefully decou-pled through low-ESR capacitors, the ESD current through the diode clamp could cause a significant spike in the supplies. This may damage or compromise the reliability of any other chip powered by those same supplies.There are diodes from NC/NO to the supplies in addi-tion to the SCRs. A resistance in series with each of these diodes limits the current into the supplies during an ESD strike. The diodes protect these terminals from overvoltages that are not a result of ESD strikes. These diodes also protect the device from improper power-supply sequencing.Once the SCR turns on because of an ESD strike, it remains on until the current through it falls below its “holding current.” The holding current is typically 110mA in the positive direction (current flowing into the NC/NO terminal) at room temperature (see SCR Holding Current vs.Temperature in the Typical Operating Characteristics ). Design the system so that any sources connected to NC/NO are current-limited to a value below the holding current to ensure the SCR turns off when the ESD event is finished and normal operation resumes. Also, remember that the holding current varies significantly with temperature. The worst case is at +85°C when the holding currents drop to 70mA. Since this is a typical number to guarantee turn-off of the SCRs under all conditions, the sources con-nected to these terminals should be current-limited to no more than half this value. When the SCR is latched,the voltage across it is approximately 3V. The supply voltages do not affect the holding current appreciably.The sources connected to the COM side of the switches need not be current limited since the switches turn off internally when the corresponding SCR(s) latch.Even though most of the ESD current flows to GND through the SCRs, a small portion of it goes into V+.Therefore, it is a good idea to bypass the V+ with 0.1µF capacitors directly to the ground plane.ESD protection can be tested in various ways. Inputs are characterized for protection to the following:•±15kV using the Human Body Model•±8kV using the Contact Discharge method speci-fied in IEC 1000-4-2 (formerly IEC 801-2)•±15kV using the Air-Gap Discharge method speci-fied in IEC 1000-4-2 (formerly IEC 801-2)ESD Test ConditionsContact Maxim Integrated Products for a reliability report that documents test setup, methodology, and results.Human Body ModelFigure 6 shows the Human Body Model, and Figure 7shows the waveform it generates when discharged into a low impedance. This model consists of a 100pF capacitor charged to the ESD voltage of interest, which can be dis-charged into the test device through a 1.5k Ωresistor.IEC 1000-4-2The IEC 1000-4-2 standard covers ESD testing and performance of finished equipment; it does not specifi-cally refer to integrated circuits. The MAX4561 enables the design of equipment that meets Level 4 (the highest level) of IEC 1000-4-2, without additional ESD protec-tion components.The major difference between tests done using the Human Body Model and IEC 1000-4-2 is higher peak cur-rent in IEC 1000-4-2. Because series resistance is lower in the IEC 1000-4-2 ESD test model (Figure 8), the ESD withstand voltage measured to this standard is generally lower than that measured using the Human Body Model.Figure 9 shows the current waveform for the ±8kV IEC 1000-4-2 Level 4 ESD Contact Discharge test.The Air-Gap test involves approaching the device with a charged probe. The Contact Discharge method connects the probe to the device before the probe is energized.Chip InformationPROCESS: CMOSBeyond-the-Rails is a trademark of Maxim Integrated Products.TRANSISTOR COUNT: 69(MAX4561)39(MAX4568/MAX4569)M A X 4561/M A X 4568/M A X 4569±15kV ESD-Protected, Low-Voltage,SPDT/SPST, CMOS Analog Switches 8_______________________________________________________________________________________Figure 1. Switching TimeFigure 2. Break-Before-Make IntervalFigure 3. Charge Injection Test Circuits/Timing DiagramsMAX4561/MAX4568/MAX4569±15kV ESD-Protected, Low-Voltage,SPDT/SPST, CMOS Analog Switches_______________________________________________________________________________________9Figure 4. Channel On/Off-CapacitanceFigure 5. Off-Isolation/On-ChannelFigure 6. Human Body ESD Test ModelFigure 7. Human Body Model Current WaveformFigure 8. IEC 1000-4-2 ESD Test Model Figure 9. IED 1000-4-2 ESD Generator Current WaveformTest Circuits/Timing Diagrams (continued)M A X 4561/M A X 4568/M A X 4569±15kV ESD-Protected, Low-Voltage,SPDT/SPST, CMOS Analog Switches 10______________________________________________________________________________________Package InformationMAX4561/MAX4568/MAX4569±15kV ESD-Protected, Low-Voltage,SPDT/SPST, CMOS Analog Switches______________________________________________________________________________________11Package Information (continued)M A X 4561/M A X 4568/M A X 4569±15kV ESD-Protected, Low-Voltage,SPDT/SPST, CMOS Analog SwitchesMaxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.12____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600©2000 Maxim Integrated Products Printed USAis a registered trademark of Maxim Integrated Products.NOTES。

MAX485典型电路ppt课件

第9章串行接口技术 4）写操作
下面以MAX485为例来介绍RS－485串行接口的应用。MAX485
的封装有DIP、SO和uMAX三种，其中DIP封装的管脚如图9.1所示。
管脚的功能如下：
RO：接收器输出端。若A比B大200mV，RO为高；反之为低电平。
RE：接收器输出使能端。RE为低时，RO有效；为高时，RO呈高阻
状态。
DE：驱动器输出使能端。若DE＝1，驱动器输
第9章串行接口技术
(2)发送应答位和非应答位子程序
IIC总线上的第9个时钟对应于应答位，相应数据线上“0” 为“ACK”和“1”为“”。发送应答位和非应答位的子程序分别如下。
①发送应答位ACK MACK： CLR SDA
SETB SCL NOP NOP CLR SCL SETB SDA RET
该子程序的入口条件是待发送的字节位于累加器ACC中。
WRB： MOV R7，#8 WLP： RLC A ；欲发送位移入C JC WR1 ；此位为1，转WR1 CLR SDA ；此位为0，发送0
SETB SCL
NOP
NOP
CLR SCL DJNZ R7，WLP ；未发完8位，转WLP
RET
；8位已发完，返回
9.2.3 典型IIC串行存储器的扩展 9.2.3.1 串行IIC总线EEPROM AT24CXX的扩展
1）基本原理 AT24CXX的特点是：单电源供电，工作电压范围宽1.8V～5.5V；低功耗 CMOS技术(100KHz(2.5 V)和400KHz(5V)兼容)，自定时写周期(包含自动擦除)、页面写周期的典型值为2ms，具有硬件写保护。
第9章串行接口技术
②控制字节的第5～7位为1～8片的片选或存贮器内的块地址选择位。此三个控制位用于选片或者内部块选择。标准的IIC规程允许选择16K位的存贮器。通过对几片器件或一个器件内的几个块的存取，可完成对16K 位存贮器的选择，如表9-6所示。

MAX1951ESA+T中文资料

General DescriptionThe MAX1951/MAX1952 high-efficiency, DC-to-DC step-down switching regulators deliver up to 2A of out-put current. The devices operate from an input voltage range of 2.6V to 5.5V and provide an output voltage from 0.8V to V IN , making the MAX1951/MAX1952 ideal for on-board postregulation applications. The MAX1951total output error is less than 1% over load, line, and temperature.The MAX1951/MAX1952 operate at a fixed frequency of 1MHz with an efficiency of up to 94%. The high operating frequency minimizes the size of external components.Internal soft-start control circuitry reduces inrush current.Short-circuit and thermal-overload protection improve design reliability.The MAX1951 provides an adjustable output from 0.8V to V IN , whereas the MAX1952 has a preset output of 1.8V. Both devices are available in a space-saving 8-pin SO package.ApplicationsASIC/DSP/µP/FPGA Core and I/O Voltages Set-Top Boxes Cellular Base StationsNetworking and TelecommunicationsFeatureso Compact 0.385in 2Circuit Footprinto 10µF Ceramic Input and Output Capacitors, 2µH Inductor for 1.5A Output o Efficiency Up to 94%o 1% Output Accuracy Over Load, Line, and Temperature (MAX1951, Up to 1.5A)o Guaranteed 2A Output Current o Operate from 2.6V to 5.5V Supplyo Adjustable Output from 0.8V to V IN (MAX1951)o Preset Output of 1.8V (1.5% Accuracy) (MAX1952)o Internal Digital Soft-Softo Short-Circuit and Thermal-Overload ProtectionMAX1951/MAX19521MHz, All-Ceramic, 2.6V to 5.5V Input,2A PWM Step-Down DC-to-DC Regulators________________________________________________________________Maxim Integrated Products 1Ordering Information19-2622; Rev 1; 8/03For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .Typical Operating CircuitPin ConfigurationM A X 1951/M A X 19521MHz, All-Ceramic, 2.6V to 5.5V Input,2A PWM Step-Down DC-to-DC Regulators 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICSStresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.IN, V CC to GND........................................................-0.3V to +6V COMP, FB, REF to GND.............................-0.3V to (V CC + 0.3V)LX to Current (Note 1).........................................................±4.5A PGND to GND.............................................Internally Connected Continuous Power Dissipation (T A = +85°C)8-Pin SO (derate 12.2mW/°C above +70°C)................976mWOperating Temperature RangeMAX195_ ESA..................................................-40°C to +85°C Junction Temperature Range............................-40°C to +150°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10s).................................+300°CNote 1:LX has internal clamp diodes to PGND and IN. Applications that forward bias these diodes should take care not to exceedthe IC ’s package power dissipation limits.MAX1951/MAX19521MHz, All-Ceramic, 2.6V to 5.5V Input,2A PWM Step-Down DC-to-DC Regulators_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS (continued)(V IN = V CC = 3.3V, PGND = GND, FB in regulation, C REF = 0.1µF, T A = 0°C to +85°C , unless otherwise noted. Typical values are at T A = +25°C.)ELECTRICAL CHARACTERISTICSM A X 1951/M A X 19521MHz, All-Ceramic, 2.6V to 5.5V Input,2A PWM Step-Down DC-to-DC Regulators 4_______________________________________________________________________________________Note 3:The LX output is designed to provide 2.4A RMS current.ELECTRICAL CHARACTERISTICS (continued)(V IN = V CC = 3.3V, PGND = GND, FB in regulation, C REF = 0.1µF, T A = -40°C to +85°C , unless otherwise noted.) (Note 2)MAX1951/MAX19521MHz, All-Ceramic, 2.6V to 5.5V Input,2A PWM Step-Down DC-to-DC Regulators_______________________________________________________________________________________5EFFICIENCY vs. LOAD CURRENT(V CC = V IN = 5V)LOAD CURRENT (mA)E F F I C I E N C Y (%)100010010203040506070809010001010,000EFFICIENCY vs. LOAD CURRENT(V CC = V IN = 3.3V)LOAD CURRENT (mA)E F F I C I E N C Y (%)100010010203040506070809010001010,000REF VOLTAGEvs. REF OUTPUT CURRENTREF OUTPUT CURRENT (µA)R E F V O L T A G E (V )35302520151051.9901.9911.9921.9931.9941.9951.98940SWITCHING FREQUENCY vs. INPUT VOLTAGEINPUT VOLTAGE (V)S W I T C H I N G F R E Q U E N C Y (M H z )5.14.63.13.64.10.850.900.951.001.051.101.151.200.802.65.6OUTPUT VOLTAGE DEVIATIONvs. LOAD CURRENTLOAD CURRENT (A)O U T P U T V O L T A G ED E V I A T I O N (m V)1.20.80.4-5-4-3-2-10123456-61.6Typical Operating Characteristics(Typical values are at V IN = V CC = 5V, V OUT = 1.5V, I OUT = 1.5A, and T A = +25°C, unless otherwise noted. See Figure 2.)LOAD TRANSIENT RESPONSEMAX1951 toc0640µs/div0OUTPUT VOLTAGE:100mV/div, AC-COUPLED OUTPUT CURRENT:0.5A/div V IN = 5V V OUT = 2.5V I OUT = 0.5 TO 1ALOAD TRANSIENT RESPONSEMAX1951 toc0740µs/divOUTPUT VOLTAGE:100mV/div, AC-COUPLEDOUTPUT CURRENT:0.5A/div V IN = 3.3V V OUT = 1.5V I OUT = 0.5 TO 1AM A X 1951/M A X 19521MHz, All Ceramic, 2.6V to 5.5V Input,2A PWM Step-Down DC-to-DC Regulators 6_______________________________________________________________________________________Typical Operating Characteristics (continued)(Typical values are at V IN = V CC = 5V, V OUT = 1.5V, I OUT = 1.5A, and T A = +25°C, unless otherwise noted. See Figure 2.)SHUTDOWN CURRENT vs. INPUT VOLTAGEM A X 1951 t o c 12INPUT VOLTAGE (V)S H U T D O W N C U R R E N T (m A )5.04.54.03.53.00.10.20.30.40.50.60.70.80.91.002.55.5SWITCHING WAVEFORMSMAX1951 toc08200ns/div0INDUCTOR CURRENT 1A/divV LX 5V/divOUTPUT VOLTAGE 10mV/div, AC-COUPLEDV IN = 3.3V V OUT = 1.8V I LOAD = 1.5ASOFT-START WAVEFORMSMAX1951 toc091ms/divV COMP 2V/divOUTPUT VOLTAGE 1V/divV IN = V CC = 3.3V V OUT = 2.5V I LOAD = 1.5ASOFT-START WAVEFORMSMAX1951 toc101ms/divV COMP 2V/divOUTPUT VOLTAGE 0.5V/divV IN = V CC = 3.3V V OUT = 0.8VSHUTDOWN WAVEFORMSMAX1951 toc1120µs/divV COMP 2V/divV LX 5V/divOUTPUT VOLTAGE 1V/divV IN = V CC = 3.3V V OUT = 2.5V I LOAD = 1.5AMAX1951/MAX19521MHz, All-Ceramic, 2.6V to 5.5V Input,2A PWM Step-Down DC-to-DC Regulators_______________________________________________________________________________________7Detailed DescriptionThe MAX1951/MAX1952 high-efficiency switching regula-tors are small, simple, DC-to-DC step-down converters capable of delivering up to 2A of output current. The devices operate in pulse-width modulation (PWM) at a fixed frequency of 1MHz from a 2.6V to 5.5V input voltage and provide an output voltage from 0.8V to V IN , making the MAX1951/MAX1952 ideal for on-board postregula-tion applications. The high switching frequency allows for the use of smaller external components, and internal synchronous rectifiers improve efficiency and eliminate the typical Schottky free-wheeling diode. Using the on-resistance of the internal high-side MOSFET to sense switching currents eliminates current-sense resistors,further improving efficiency and cost. The MAX1951total output error over load, line, and temperature (0°C to +85°C) is less than 1%.Controller Block FunctionThe MAX1951/MAX1952 step-down converters use a PWM current-mode control scheme. An open-loop com-parator compares the integrated voltage-feedback signal against the sum of the amplified current-sense signal and the slope compensation ramp. At each rising edge of the internal clock, the internal high-side MOSFET turns on until the PWM comparator trips. During this on-time, cur-rent ramps up through the inductor, sourcing current to the output and storing energy in the inductor. The current-mode feedback system regulates the peak inductor cur-rent as a function of the output voltage error signal. Since the average inductor current is nearly the same as the peak inductor current (<30% ripple current), the circuit acts as a switch-mode transconductance amplifier. To preserve inner-loop stability and eliminate inductor stair-casing, a slope-compensation ramp is summed into the main PWM comparator. During the second half of the cycle, the internal high-side P-channel MOSFET turns off,and the internal low-side N-channel MOSFET turns on.The inductor releases the stored energy as its current ramps down while still providing current to the output. The output capacitor stores charge when the inductor current exceeds the load current, and discharges when the inductor current is lower, smoothing the voltage across the load. Under overload conditions, when the inductor current exceeds the current limit (see the Current Limit section), the high-side MOSFET does not turn on at the rising edge of the clock and the low-side MOSFET remains on to let the inductor current ramp down.Current SenseAn internal current-sense amplifier produces a current signal proportional to the voltage generated by the high-side MOSFET on-resistance and the inductor cur-rent (R DS(ON) x I LX ). The amplified current-sense signal and the internal slope compensation signal are summed together into the comparator ’s inverting input.The PWM comparator turns off the internal high-side MOSFET when this sum exceeds the output from the voltage-error amplifier.Current LimitThe internal high-side MOSFET has a current limit of 3.1A (typ). If the current flowing out of LX exceeds this limit,the high-side MOSFET turns off and the synchronous rectifier turns on. This lowers the duty cycle and causes the output voltage to droop until the current limit is no longer exceeded. A synchronous rectifier current limit of -0.6A (typ) protects the device from current flowing into LX. If the negative current limit is exceeded, the synchro-nous rectifier turns off, forcing the inductor current to flowM A X 1951/M A X 19521MHz, All-Ceramic, 2.6V to 5.5V Input,2A PWM Step-Down DC-to-DC Regulators 8_______________________________________________________________________________________through the high-side MOSFET body diode, back to the input, until the beginning of the next cycle or until the inductor current drops to zero. The MAX1951/MAX1952utilize a pulse-skip mode to prevent overheating during short-circuit output conditions. The device enters pulse-skip mode when the FB voltage drops below 300mV, lim-iting the current to 3A (typ) and reducing power dissipation. Normal operation resumes upon removal of the short-circuit condition.V CC DecouplingDue to the high switching frequency and tight output tolerance (1%), decouple V CC with a 0.1µF capacitor connected from V CC to GND, and a 10Ωresistor con-nected from V CC to IN. Place the capacitor as close to V CC as possible.Soft-StartThe MAX1951/MAX1952 employ digital soft-start circuitry to reduce supply inrush current during startup conditions.When the device exits undervoltage lockout (UVLO), shut-down mode, or restarts following a thermal-overload event, or the external pulldown on COMP is released, the digital soft-start circuitry slowly ramps up the voltages at REF and FB (see the Soft-Start Waveforms in the Typical Operating Characteristics).Undervoltage LockoutIf V CC drops below 2.25V, the UVLO circuit inhibits switching. Once V CC rises above 2.35V, the UVLO clears, and the soft-start sequence activates.Compensationand Shutdown ModeThe output of the internal transconductance voltage error amplifier connects to COMP. The normal operation voltage for COMP is 1V to 2.2V. To shut down the MAX1951/MAX1952, use an NPN bipolar junction transistor or a very low output capacitance open-drain MOSFET to pull COMP to GND. Shutdown mode causes the internal MOSFETs to stop switching, forces LX to a high-impedance state, and shorts REF to G ND.Release COMP to exit shutdown and initiate the soft-start sequence.Thermal-Overload ProtectionThermal-overload protection limits total power dissipation in the device. When the junction temperature exceeds T J = +160°C, a thermal sensor forces the device into shut-down, allowing the die to cool. The thermal sensor turns the device on again after the junction temperature cools by 15°C, resulting in a pulsed output during continuous overload conditions. Following a thermal-shutdown condi-tion, the soft-start sequence begins.Figure 1. Functional DiagramMAX1951/MAX19521MHz, All-Ceramic, 2.6V to 5.5V Input,2A PWM Step-Down DC-to-DC Regulators_______________________________________________________________________________________9Design ProcedureOutput Voltage Selection: Adjustable(MAX1951) or Preset (MAX1952)The MAX1951 provides an adjustable output voltage between 0.8V and V IN . Connect FB to output for 0.8V output. To set the output voltage of the MAX1951 to a voltage greater than V FB (0.8V typ), connect the output to FB and G ND using a resistive divider, as shown in Figure 2a. Choose R2 between 2k Ωand 20k Ω, and set R3 according to the following equation:R3 = R2 x [(V OUT / V FB ) – 1]The MAX1951 PWM circuitry is capable of a stable min-imum duty cycle of 18%. This limits the minimum output voltage that can be generated to 0.18 ✕V IN . Instability may result for V IN /V OUT ratios below 0.18.The MAX1952 provides a preset output voltage.Connect the output to FB, as shown in Figure 2b.Output Inductor DesignUse a 2µH inductor with a minimum 2A-rated DC cur-rent for most applications. For best efficiency, use an inductor with a DC resistance of less than 20m Ωand a saturation current greater than 3A (min). See Table 2for recommended inductors and manufacturers. For most designs, derive a reasonable inductor value (L INIT ) from the following equation:L INIT = V OUT x (V IN - V OUT ) / (V IN x LIR x I OUT(MAX)x f SW )where f SW is the switching frequency (1MHz typ) of the oscillator. Keep the inductor current ripple percentage LIR between 20% and 40% of the maximum load cur-rent for the best compromise of cost, size, and perfor-mance. Calculate the maximum inductor current as:I L(MAX)= (1 + LIR / 2) x I OUT(MAX)Check the final values of the inductor with the output ripple voltage requirement. The output ripple voltage is given by:V RIPPLE = V OUT x (V IN - V OUT ) x ESR / (V IN x L FINAL x f SW )where ESR is the equivalent series resistance of the output capacitors.Input Capacitor DesignThe input filter capacitor reduces peak currents drawn from the power source and reduces noise and voltage ripple on the input caused by the circuit ’s switching.The input capacitor must meet the ripple current requirement (I RMS ) imposed by the switching currents defined by the following equation:For duty ratios less than 0.5, the input capacitor RMS current is higher than the calculated current. Therefore,use a +20% margin when calculating the RMS current at lower duty cycles. Use ceramic capacitors for their low ESR, equivalent series inductance (ESL), and lower cost. Choose a capacitor that exhibits less than 10°C temperature rise at the maximum operating RMS cur-rent for optimum long-term reliability.After determining the input capacitor, check the input ripple voltage due to capacitor discharge when the high-side MOSFET turns on. Calculate the input ripple voltage as follows:V IN_RIPPLE = (I OUT x V OUT ) / (f SW x V IN x C IN )Keep the input ripple voltage less than 3% of the input voltage.Output Capacitor DesignThe key selection parameters for the output capacitor are capacitance, ESR, ESL, and the voltage rating requirements. These affect the overall stability, output ripple voltage, and transient response of the DC-to-DC converter. The output ripple occurs due to variations in the charge stored in the output capacitor, the voltage drop due to the capacitor ’s ESR, and the voltage drop due to the capacitor ’s ESL. Calculate the output voltage ripple due to the output capacitance, ESR, and ESL as:V RIPPLE = V RIPPLE(C)+ V RIPPLE(ESR) + V RIPPLE(ESL)where the output ripple due to output capacitance,ESR, and ESL is:V RIPPLE(C)= I P-P / (8 x C OUT x f SW )V RIPPLE(ESR) = I P-P x ESRV RIPPLE(ESL)= (I P-P / t ON ) x ESL or (I P-P / t OFF ) x ESL,whichever is greater and I P-P the peak-to-peak inductor current is:I P-P = [ (V IN – V OUT ) / f SW x L) ] x V OUT / V INUse these equations for initial capacitor selection, but determine final values by testing a prototype or evalua-tion circuit. As a rule, a smaller ripple current results in less output voltage ripple. Since the inductor ripple current is a factor of the inductor value, the output voltage ripple decreases with larger inductance. Use ceramic capacitors for their low ESR and ESL at the switching frequency of the converter. The low ESL of ceramic capacitors makes ripple voltages negligible.Load transient response depends on the selected output capacitor. During a load transient, the output instantly changes by ESR x I LOAD . Before the controller can respond, the output deviates further, depending on the inductor and output capacitor values. After a short time (see the Load Transient Response graphin theM A X 1951/M A X 19521MHz, All-Ceramic, 2.6V to 5.5V Input,2A PWM Step-Down DC-to-DC Regulators 10______________________________________________________________________________________Typical Operating Characteristic s), the controller responds by regulating the output voltage back to its nominal state. The controller response time depends on the closed-loop bandwidth. A higher bandwidth yields a faster response time, thus preventing the output from deviating further from its regulating value.Compensation DesignThe double pole formed by the inductor and output capacitor of most voltage-mode controllers introduces a large phase shift, which requires an elaborate compensa-tion network to stabilize the control loop. The MAX1951/MAX1952 utilize a current-mode control scheme that reg-ulates the output voltage by forcing the required current through the external inductor, eliminating the double pole caused by the inductor and output capacitor, and greatly simplifying the compensation network. A simple type 1compensation with single compensation resistor (R 1) and compensation capacitor (C 2) creates a stable and high-bandwidth loop.An internal transconductance error amplifier compen-sates the control loop. Connect a series resistor and capacitor between COMP (the output of the error ampli-fier) and G ND to form a pole-zero pair. The external inductor, internal current-sensing circuitry, output capacitor, and the external compensation circuit deter-mine the loop system stability. Choose the inductor and output capacitor based on performance, size, and cost.Additionally, select the compensation resistor and capacitor to optimize control-loop stability. The compo-nent values shown in the typical application circuit (Figure 2) yield stable operation over a broad range of input-to-output voltages.The basic regulator loop consists of a power modulator,an output feedback divider, and an error amplifier. The power modulator has DC gain set by gmc x R LOAD ,with a pole-zero pair set by R LOAD , the output capaci-tor (C OUT ), and its ESR. The following equations define the power modulator:Modulator gain:G MOD = ∆V OUT / ∆V COMP = gmc x R LOAD Modulator pole frequency:fp MOD = 1 / (2 x πx C OUT x (R LOAD +ESR))Modulator zero frequency:fz ESR = 1 / (2 x πx C OUT x ESR)where, R LOAD = V OUT / I OUT(MAX), and gmc = 4.2S.The feedback divider has a gain of G FB = V FB / V OUT ,where V FB is equal to 0.8V. The transconductance error amplifier has a DC gain, G EA(DC),of 70dB. The com-pensation capacitor, C 2,and the output resistance of the error amplifier, R OEA (20M Ω), set the dominantpole. C 2and R 1 set a compensation zero. Calculate the dominant pole frequency as:fp EA = 1 / (2πx C C x R OEA )Determine the compensation zero frequency is:fz EA = 1 / (2πx C C x R C )For best stability and response performance, set the closed-loop unity-gain frequency much higher than the modulator pole frequency. In addition, set the closed-loop crossover unity-gain frequency less than, or equal to, 1/5 of the switching frequency. However, set the maximum zero crossing frequency to less than 1/3 of the zero frequency set by the output capacitance and its ESR when using POSCAP, SPCAP, OSCON, or other electrolytic capacitors.The loop-gain equation at the unity-gain frequency is:G EA(fc) x G MOD(fc) x V FB / V OUT = 1where G EA(fc )= gm EA x R 1, and G MOD(fc)= gmc x R LOAD x fp MOD /f C, where gm EA = 60µS .R 1calculated as:R 1= V OUT x K / (gm EA x V FB x G MOD(fc))where K is the correction factor due to the extra phase introduced by the current loop at high frequencies (>100kHz). K is related to the value of the output capacitance (see Table 1 for values of K vs. C). Set the error-amplifier compensation zero formed by R 1and C 2at the modulator pole frequency at maximum load. C 2is calculated as follows:C 2= (2 x V OUT x C OUT / (R 1 x I OUT(MAX))As the load current decreases, the modulator pole also decreases; however, the modulator gain increases accordingly, resulting in a constant closed-loop unity-gain frequency. Use the following numerical example to calculate R 1and C 2values of the typical application circuit of Figure 2a.Table 1. K ValueV OUT = 1.5VI OUT(MAX)= 1.5A C OUT = 10µF R ESR = 0.010Ωgm EA = 60µSMAX1951/MAX19521MHz, All-Ceramic, 2.6V to 5.5V Input,2A PWM Step-Down DC-to-DC Regulators______________________________________________________________________________________11gmc = 4.2Sf SWITCH = 1MHzR LOAD = V OUT / I OUT(MAX)= 1.5V / 1.5 A = 1Ωfp MOD = [1 / (2πx C OUT x (R LOAD + R ESR )]= [1 / (2 x π×10 ×10-6x (1 + 0.01)] = 15.76kHz.fz ESR = [1/(2πxC OUT R ESR )]= [1 / (2 x π×10 ×10-6×0.01)] = 1.59MHz.For 2µH output inductor, pick the closed-loop unity-gain crossover frequency (f C ) at 200kHz. Determine the power modulator gain at f C :G MOD(fc )= gmc ×R LOAD ×fp MOD / f C = 4.2 ×1 ×15.76kHz / 200kHz = 0.33then:R 1= V O x K / (gm EA x V FB x G MOD(fc )) = (1.5 x 0.55) /(60 ×10-6 ×0.8 ×0.33) ≈51.1k Ω(1%)C 2= (2 x V OUT ×C OUT ) / (R C ×I OUT(max))= (2 ×1.25 × 10 × 10-6)/ (51.1k ×1.5) ≈209pF, choose 220pF, 10%Applications InformationPC Board Layout ConsiderationsCareful PC board layout is critical to achieve clean and stable operation. The switching power stage requires particular attention. Follow these guidelines for good PC board layout:1)Place decoupling capacitors as close to the IC as possible. Keep power ground plane (connected to PG ND) and signal ground plane (connected to GND) separate.2)Connect input and output capacitors to the power ground plane; connect all other capacitors to the signal ground plane.3)Keep the high-current paths as short and wide as possible. Keep the path of switching current (C1 to IN and C1 to PG ND) short. Avoid vias in the switching paths.4)If possible, connect IN, LX, and PGND separately to a large copper area to help cool the IC to further improve efficiency and long-term reliability.5)Ensure all feedback connections are short and direct. Place the feedback resistors as close to the IC as possible.6)Route high-speed switching nodes away from sensi-tive analog areas (FB, COMP).Thermal ConsiderationsThe MAX1951 uses a fused-lead 8-pin SO package with a R THJC rating of 32°C/W. The MAX1951 EV kit layout is optimized for 1.5A. The typical application circuit shown in Figure 2c was tested with the existing MAX1951 EV kit layout at +85°C ambient temperature, and G ND lead temperature was measured at +113°C for a typical device. The estimated junction temperature was +138°C. Thermal performance can be further improved with one of the following options:1) Increase the copper areas connected to G ND, LX,and IN.2) Provide thermal vias next to G ND and IN, to the ground plane and power plane on the back side of PC board, with openings in the solder mask next to the vias to provide better thermal conduction.3) Provide forced-air cooling to further reduce case temperature.M A X 1951/M A X 19521MHz, All-Ceramic, 2.6V to 5.5V Input,2A PWM Step-Down DC-to-DC Regulators 12______________________________________________________________________________________Figure 2a. MAX1951 Adjustable Output Typical Application CircuitFigure 2b. MAX1952 Fixed-Output Typical Application CircuitMAX1951/MAX19521MHz, All-Ceramic, 2.6V to 5.5V Input,2A PWM Step-Down DC-to-DC Regulators______________________________________________________________________________________13Figure 2c. MAX1951 Typical Application Circuit with 2A OutputM A X 1951/M A X 19521MHz, All-Ceramic, 2.6V to 5.5V Input,2A PWM Step-Down DC-to-DC Regulators 14______________________________________________________________________________________Chip InformationTRANSISTOR COUNT: 2500PROCESS: BiCMOSMAX1951/MAX19521MHz, All-Ceramic, 2.6V to 5.5V Input,2A PWM Step-Down DC-to-DC RegulatorsMaxim cannot assume responsibility for use of any circuitry other than circuitry entirely embod ied in a Maxim prod uct. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________15©2003 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.Package Information(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to /packages .)。

MAX1241中文资料datasheet

总体说明
MAX1240 / MAX1241 采用 8 引脚封装的低功耗、12 位模数转换器转换器（ADC）。 MAX1240 采用 + 2.7V 至 + 3.6V 的电源供电，MAX1241 采用单电源供电范围是+ 2.7V 至+ 5.25V。这两款设备都具有 7.5μs 的功能逐次逼近 ADC，快速跟踪/保持（1.5μs），片上时钟和高速 3 线串行接口。在 73ksps 的最大采样速度下，功耗仅为 37mW（VDD = 3V）。2μA 关断模式以较慢的吞吐率来降低功耗。 MAX1240 具有内部 2.5V 参考电压，而 MAX1241 需要外部参考电压。MAX1241 接受从 0V 到VREF 和参考信号输入范围包括正电源轨。外部的时钟从 3 线接口访问数据，它直接连接到标准微控制器的 I/O 港口。该接口与 SPI™，QSPI™和 MICROWIRE™兼容。该接卓越的交流特性和极低的功耗，易于使用和小封装尺寸，使这些转换器成为远程传感器和数据采集应用的理想之选，或者是要求降低功耗和对空间有要求的电路的最好选择。MAX1240/MAX1241 采用 8 引脚 PDIP 和 SO 封装。
兑换率
转换时间跟踪/保持采集时间转换时间吞吐率光圈抖动
tCONV
t ACQ
t APR
fSCLK=2.1MHz 图8
5.5
7.5
us
1.5
us
73
ksps
30
ns
<50
ps
模拟输入
输入电压范围输入电容
0
VREF V
16
pF
电源要求

MEMORY存储芯片MAX3490ECSA+T中文规格书

Figure 22. MAX3488/MAX3490/MAX3491 Full-Duplex RS-485 NetworkFigure 23. Line Repeater for MAX3488/MAX3490/MAX3491MAX3483/MAX3485/MAX3486/MAX3488/MAX3490/MAX34913.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 TransceiversLine Length vs. Data Rate The RS-485/RS-422 standard covers line lengths up to 4000 feet. For line lengths greater than 4000 feet, see Figure 23.Figures 19 and 20 show the system differential voltage for parts driving 4000 feet of 26AWG twisted-pair wire at 125kHz into 120Ω loads.Typical ApplicationsThe MAX3483, MAX3485, MAX3486, MAX3488, MAX3490, and MAX3491 transceivers are designed for bidirectional data communications on multipoint bus transmission lines. Figures 21 and 22 show typical net-work applications circuits. These parts can also be used as line repeaters, with cable lengths longer than 4000 feet, as shown in Figure 23.To minimize reflections, the line should be terminated at both ends in its characteristic impedance, and stub lengths off the main line should be kept as short as pos-sible. The slew-rate-limited MAX3483/MAX3488 and the partially slew-rate-limited MAX3486 are more tolerant of imperfect termination.MAX3483/MAX3485/MAX3486/MAX3488/MAX3490/MAX34913.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers Figure 21. MAX3483/MAX3485/MAX3486 Typical RS-485 Network Driver Output ProtectionExcessive output current and power dissipation caused by faults or by bus contention are prevented by two mechanisms. A foldback current limit on the output stage provides immediate protection against short circuits over the whole common-mode voltage range (see Typical Operating Characteristics ). In addition, a thermal shut-down circuit forces the driver outputs into a high-impedance state if the die temperature rises excessively.Propagation Delay Figures 15–18 show the typical propagation delays. Skew time is simply the difference between the low-to-high and high-to-low propagation delay. Small driver/receiver skew times help maintain a symmetrical mark-space ratio (50% duty cycle).The receiver skew time, |t PRLH - t PRHL |, is under 10ns (20ns for the MAX3483/MAX3488). The driver skew times are 8ns for the MAX3485/MAX3490/MAX3491, 11ns for the MAX3486, and typically under 100ns for the MAX3483/MAX3488.。

MAX5201AEUB+中文资料

General DescriptionThe MAX5200–MAX5203 serial input, voltage-output,16-bit digital-to-analog converters (DACs) provide monotonic 16-bit output over temperature without any adjustments. The MAX5200/MAX5201 operate from a +5V single power supply featuring an internal reference of +2.5V and an internal gain of 2, while the MAX5202/MAX5203 operate from a +3V or +3.3V single power supply featuring an internal reference of +1.5V and an internal gain of 2. The MAX5200–MAX5203 DAC output range is typically from 0 to V DD .The MAX5200–MAX5203 feature a hardware reset input (CLR ) that, when pulled low, clears the output to zero code 0000 hex (MAX5201/MAX5203) or resets the out-put to midscale code 8000 hex (MAX5200/MAX5202). The 3-wire serial interface is compatible with SPI ™/QSPI ™/MI CROWI RE™. All devices have a low-power shutdown mode that reduces the supply current consumption to 1µA.The MAX5200–MAX5203 are available in a space-sav-ing 10-pin µMAX ®package and are guaranteed over the extended temperature range (-40°C to +105°C).Refer to the MAX5204–MAX5207 data sheet for external reference versions.ApplicationsLow-Cost VCO/VCXO Frequency Control Industrial Process Control High-Resolution Offset AdjustmentFeatures♦Guaranteed 16-Bit Monotonic ♦Internal Reference♦10-Pin 5mm ✕3mm µMAX Package ♦Rail-to-Rail Output Amplifier ♦Single-Supply Operation+5V (MAX5200/MAX5201)+3V, +3.3V (MAX5202/MAX5203)♦Low Power Consumption: 0.8mA♦Shutdown Mode Reduces Supply Current to 1µA ♦SPI/QSPI/MICROWIRE-Compatible 3-Wire Serial Interface ♦Power-On-Reset Sets Output toMidscale (MAX5200/MAX5202)Zero Scale (MAX5201/MAX5203)MAX5200–MAX5203Low-Cost, Voltage-Output, 16-Bit DACs withInternal Reference in µMAX________________________________________________________________Maxim Integrated Products1Pin Configuration19-2655; Rev 2; 10/04For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .SPI/QSPI are trademarks of Motorola, Inc.MICROWIRE is a trademark of National Semiconductor Corp.µMAX is a registered trademark of Maxim Integrated Products, Inc.Selector Guide appears at end of data sheet.Ordering InformationM A X 5200–M A X 5203Low-Cost, Voltage-Output, 16-Bit DACs with Internal Reference in µMAX 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSStresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.V DD to AGND, DGND...............................................-0.3V to +6V AGND to DGND.........................................……….-0.3V to +0.3V REF, OUT to AGND.................................…-0.3V to (V DD + 0.3V)CLR , LDAC , SCLK, DIN, CS to DGND.......-0.3V to (V DD + 0.3V)Maximum Current into Any Pin............................................50mA Continuous Power Dissipation (T A = +70°C)10-Pin µMAX (derate 5.6mW/°C above +70°C)........444.4mWOperating Temperature RangesMAX520_CUB.....................................................0°C to +70°C MAX520_EUB........................................…….-40°C to +105°C Junction Temperature......................................................+150°C Storage Temperature Range.............................-60°C to +150°C Lead Temperature (soldering, 10s).................................+300°CELECTRICAL CHARACTERISTICS—MAX5200/MAX5201MAX5200–MAX5203Low-Cost, Voltage-Output, 16-Bit DACs withInternal Reference in µMAX_______________________________________________________________________________________3ELECTRICAL CHARACTERISTICS—MAX5200/MAX5201 (continued)(V DD = +4.75V to +5.25V, f SCLK = 10MHz (50% duty cycle), output load = 10k Ωin parallel with 250pF, T A = T MIN to T MAX , unless other-wise noted. Typical values are at T A = +25°C.)M A X 5200–M A X 5203Low-Cost, Voltage-Output, 16-Bit DACs with Internal Reference in µMAX 4_______________________________________________________________________________________ELECTRICAL CHARACTERISTICS—MAX5202/MAX5203(V DD = +2.7V to +3.6V, f SCLK = 10MHz (50% duty cycle), output load = 10k Ωin parallel with 250pF, T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.)MAX5200–MAX5203Low-Cost, Voltage-Output, 16-Bit DACs withInternal Reference in µMAX_______________________________________________________________________________________5Note 2:INL and DNL are guaranteed for outputs between 0.5V to (V DD - 0.5V).Note 3:Guaranteed monotonic.Note 4:V REF = 2.5V (MAX5200/MAX5201) and V REF = 1.5V (MAX5202/MAX5203).Note 5:R L = ∞, digital inputs are at V DD or DGND.ELECTRICAL CHARACTERISTICS—MAX5202/MAX5203 (continued)(V DD = +2.7V to +3.6V, f SCLK = 10MHz (50% duty cycle), output load = 10k Ωin parallel with 250pF, T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.)10010k 100kOUTPUT NOISE DENSITYvs. FREQUENCYFREQUENCY (Hz)V O L T A G E N O I S E D E N S I T Y (n V /√H z )1k 700100200300400600500M A X 5200–M A X 5203Low-Cost, Voltage-Output, 16-Bit DACs with Internal Reference in µMAX 6_______________________________________________________________________________________SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (m A )755025-40-200.60.70.80.91.00.585INTEGRAL NONLINEARITYvs. CODEM A X 5200 t o c 02DAC CODEI N L (L S B )60,00050,00010,00020,00030,00040,000-12-8-40481216-1670,000DIFFERENTIAL NONLINEARITYvs. CODEM A X 5200 t o c 03DAC CODED N L (L S B )-0.75-0.50-0.2500.250.500.751.00-1.00060,00050,00010,00020,00030,00040,00070,000GAIN ERROR vs. TEMPERATUREM A X 5200 t o c 04TEMPERATURE (°C)G A I N E R R O R (%F S R )604020-20-0.08-0.06-0.04-0.0200.020.040.060.080.10-0.10-4080OFFSET ERROR vs. TEMPERATUREM A X 5200 t o c 05TEMPERATURE (°C)O F F S E T E R R O R (m V )-0.30-0.20-0.1000.100.200.300.40-0.40604020-20-4080HALF-SCALE OUTPUT SETTLING TIME (CODE FROM 4000H TO C000H)MAX5200 toc06a40µs/divOUT 1V/divOUT 1mV/divR LOAD = 10k ΩC LOAD = 250pFSMALL SIGNAL (1mV/div)LARGE SIGNAL (1V/div)HALF-SCALE OUTPUT SETTLING TIME (CODE FROM C000H TO 4000H)MAX5200 toc06b40µs/divOUT 1V/divOUT 1mV/divR LOAD = 10k ΩC LOAD = 250pFSMALL SIGNAL (1mV/div)LARGE SIGNAL (1V/div)Typical Operating Characteristics(V DD = +5V, T A = +25°C, unless otherwise noted.)MAX5200–MAX5203Low-Cost, Voltage-Output, 16-Bit DACs withInternal Reference in µMAX_______________________________________________________________________________________7SOURCE-CURRENT CAPABILITYSOURCE CURRENT (mA)O U T P U T V O L T A G E (V )3020100.51.01.52.02.53.03.54.04.50040SINK-CURRENT CAPABILITYSINK CURRENT (mA)O U T P U T V O L T A G E (V )129630.51.01.52.02.53.03.54.04.50015MAJOR-CARRY OUTPUT GLITCH (CODE FROM 8000H TO 7FFFH)MAX5200 toc101µs/divOUT(AC-COUPLED,5mV/div)MAJOR-CARRY OUTPUT GLITCH (CODE FROM 7FFFH TO 8000H)MAX5200 toc111µs/divOUT(AC-COUPLED,5mV/div)SHUTDOWN CURRENT vs. TEMPERATURETEMPERATURE (°C)S H U T D O W N C U R R E N T (µA )60-202040-0.75-0.50-0.2500.250.500.751.00-1.00-4080Typical Operating Characteristics (continued)(V DD = +5V, T A = +25°C, unless otherwise noted.)M A X 5200–M A X 5203Low-Cost, Voltage-Output, 16-Bit DACs with Internal Reference in µMAX 8_______________________________________________________________________________________zero code 0000H (MAX5201/MAX5203) or resets the DAC output to midscale code 8000 hex (MAX5200/MAX5202). For normal operation, connect CLR to V DD .Internal ReferenceThe MAX5200/MAX5201 (+5V supply) include an inter-nal reference of 2.5V while the MAX5202/MAX5203(+3V supply) include an internal reference of 1.5V. The DAC output range is from 0 to 2 ✕V REF . Do not drive external circuitry from this reference. To improve DAC output noise performance, bypass with a low leakage 0.1µF minimum capacitor to AGND.Digital InterfaceThe MAX5200–MAX5203 digital interface is a standard 3-wire connection compatible with SP I /QSP I/MICROWIRE and most DSP interfaces. All of the digital input pins (CS , SCLK, DI N, CLR,and LDAC ) are TTL compatible. SCLK can accept clock frequencies as high as 10MHz for a +5V supply and 10MHz for a +3V or +3.3V supply.One of two methods can be used when interfacing and updating the MAX5200–MAX5203. The first requires three digital inputs: CS , DIN, and SCLK (Figure 2). The active-low chip-select input (CS ) enables the serialFigure 1. MAX5200–MAX5203 Simplified Functional DiagramMAX5200–MAX5203Low-Cost, Voltage-Output, 16-Bit DACs withInternal Reference in µMAX_______________________________________________________________________________________9data loading at the data input (DI N). Pull CS low and clock in each bit of the 16-bit digital word on the rising edge of the serial clock (SCLK). Two 8-bit bytes can be used, and do not require any additional time between them. Pulling CS high after loading the 16-bit word transfers that code into the DAC register and then updates the output. I f CS is not kept low during the entire loading of the 16-bit word, data is corrupted. I n this case, a new 16-bit word must be loaded. LDAC must be kept low at all times for the above instructions.An alternate method of interfacing and updating the MAX5200–MAX5203 can be done with a fourth digital input, the active-low load DAC (LDAC ). LDAC allows the output to update asynchronously after CS goes high. I t is useful when updating multiple MAX5200–MAX5203s synchronously when sharing a single LDAC and CS line. LDAC must be kept high at all times dur-ing the data-loading sequence and must only be asserted when CS is high. Asserting LDAC when CS is low can cause corrupted data. To operate the MAX5200–MAX5203 using LDAC , pull LDAC high, pull CS low, load the 16-bit word as described in the previ-ous paragraph, and pull CS high again. Following these commands, the DAC output only updates when LDAC is asserted low (Figure 3).Shutdown ModeThe low-power shutdown mode reduces supply current to typically 1µA and a maximum of 10µA. Shutdown mode is not activated through command words, as is common among D/A converters. These devices require careful manipulation of CS and SCLK (Figure 4).Shutting DownTo shut down the MAX5200–MAX5203, change the state of SCLK (either a high to low or low to high transi-tion can be used) and pulse two falling CS edges. I n order to keep the device in shutdown mode, SCLK must not change state. SCLK must remain in the state it is in after the two CS pulses.Waking UpThere are two methods to wake up the MAX5200–MAX5203. Pulse one falling CS edge or transition SCLK.It takes 50µs typically from the CS falling edge or SCLK transition for the DAC to return to normal operation.Power-On ResetThe MAX5200–MAX5203 have a power-on reset circuit to set the DAC’s output to a known state when V DD is first applied. The MAX5200/MAX5202 reset to midscale (code 8000 hex) upon power-up. The MAX5201/MAX5203 reset to zero scale (code 0000 hex) upon power-up. This ensures that unwanted output voltages do not occur immediately following a system power-up, such as a loss of power. It is required to apply V DD first before any other inputs (DIN, SCLK, CLR , LDAC , and CS ).Figure 2. 3-Wire Interface Timing DiagramM A X 5200–M A X 5203Low-Cost, Voltage-Output, 16-Bit DACs with Internal Reference in µMAX 10______________________________________________________________________________________Applications InformationPower-Supply and BypassingConsiderationsBypass the power supply with a 10µF capacitor in par-allel with a 0.1µF capacitor to AGND. Minimize lead lengths to reduce lead inductance. I f noise becomes an issue, use shielding and/or ferrite beads to increase isolation.Output BufferThe MAX5200–MAX5203 include low-offset, low-noise buffers enabling the output to source 15mA or sink 5mA. The output buffer operates at a slew rate of 0.6V/µs. With a 1/4 FS to 3/4 FS output transition, the buffer output typically settles to 1 LSB in less than 25µs. The MAX5200–MAX5203 output buffers provide a low 0.2Ωtypical output impedance. The MAX5200–MAX5203 buffer amplifiers typically produce 175nV/√Hz noise at 10kHz.Figure 4. Shutdown TimingFigure 3. 4-Wire Interface Timing DiagramMAX5200–MAX5203Low-Cost, Voltage-Output, 16-Bit DACs withInternal Reference in µMAX______________________________________________________________________________________11The MAX5200–MAX5203 are designed for unipolar opera-tion, but can be used in bipolar applications with an exter-nal amplifier and resistors. Figure 5 shows the MAX5200–MAX5203 configured for bipolar operation. The op amp is set for unity gain. Table 1 lists the offset binary code for this circuit. The output voltage range is ±V REF .Layout ConsiderationsDigital and AC transient signals coupling to AGND can create noise at the output. Connect AGND to the high-est quality ground available. Use proper grounding techniques, such as a multilayer board with a low-inductance ground plane. Wire-wrapped boards and sockets are not recommended. For optimum system performance, use printed circuit (PC) boards with sep-arate analog and digital ground planes. Connect the two ground planes together at the low-impedance power-supply source. Connect DGND and AGND pins together at the I C. The best ground connection is achieved by connecting the DAC’s DGND and AGND together, and then connecting that point to the system analog ground plane. If the DAC’s DGND is connected to the system digital ground, digital noise can get through the DAC’s analog portion.Chip InformationTRANSISTOR COUNT: 8764PROCESS: BiCMOSFigure 5. MAX5200–MAX5203 Typical Operating Circuit—Bipolar OutputM A X 5200–M A X 5203Low-Cost, Voltage-Output, 16-Bit DACs with Internal Reference in µMAX 12______________________________________________________________________________________MAX5200–MAX5203Low-Cost, Voltage-Output, 16-Bit DACs withInternal Reference in µMAXMa xim ca nnot a ssume responsibility for use of a ny circuitry other tha n circuitry entirely embodied in a Ma xim product. No circuit pa tent licenses a reimplied. Maxim reserves the right to change the circuitry and specifications without notice at any time.Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________13©2004 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.Package Information(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to /packages .)。

艾森PXM4051A1BA电能表说明书

Eaton PXM4051A1BAEaton Enclosed PXMP meter, Standard power quality, 2 GB,Voltage input; (V1, V2, V3, V4), 100-240 Vac or 110-250 Vdc,Communications module with RS-485, Communications expansioncard with 10/100 Base-T, 100F, RS-485, RS-232 portsGeneral specificationsEaton Power Xpert meter 4000PXM4051A1BA7866854247819.56 in8.32 in 6.72 in7.1 lb 1 yearCE MarkedCFR 47 FCC Part 15IEC 60687ANSI/IEEE Std C12.20 UL Listed file 61010-1 EN 61010-1IEC 61326EN 60687Product Name Catalog Number UPC Product Length/Depth Product Height Product Width Product Weight Warranty Compliances Certifications4096 Oversampling/cycleTo 127thAudible AlarmTime / date stampLED alarm indicatorEvent LogEmail on alarmData LoggingMin/Max LogStandard communications module with RS-485K-FactorCrest FactorView Harmonic Spectrum At DevicePQ Index Graph -STDNumber Of 9'S AvailabilityCommunications expansion card with 10/100 Base-T, 100F, RS-485, RS-232 ports2 GBModbus TCPBACnet/IPFile Transfer Protocol (FTP) built-in1 x Local Ethernet Port for configurationInternet/HTTP Server built-in1xRS-485Current & Voltage - % Phase Unbalance - EVENT SETTING ONLYVarhFrequencyDisplacement Power FactorVaTime Of Use Energy Enterprise Data Center SolutionsEaton's Volume 3—Power Distribution and Control AssembliesPower Xpert Meter 4000/6000/8000 User Manual Addendum for DNP 3.0The New Power Xpert Meter Web Interface, Step 4: Accessing the Meter with a TabletThe New Power Xpert Meter Web Interface, Step 1: Getting Started with the New UIThe New Power Xpert Meter Web Interface, Step 3: Navigating the New UIThe New Power Xpert Meter Web Interface, Step 2: Navigating the New UIPower Xpert MetersUpgrading your Power Xpert Meter to HTML5, PXM 4/6/8K Series EditionPower Systems Experience Center Tour – Metering FocusEaton Power Xpert Meter 4000/6000/8000 power quality and energy metersWaveform capture sampling rate %Thd - current and voltage LoggingModification 1Power quality analysis Modification 2MemoryCommunications Instrumentation BrochuresCatalogsInstallation instructions MultimediaSpecifications and datasheetsDemand MeteringCurrent & Voltage - 3 Phase Min, MaxWattsCurrent & Voltage - 3 Phase AveragePer Phase Power FactorView current & voltage phasors on display Voltage Neutral-GroundCurrent DemandVarsVahVa demand4 Quadrant EnergyApparent Power FactorNeutral CurrentWh --NetGround CurrentCurrent & Voltage - Per PhaseWh --Positive & NegativeWatt DemandTypeStandard power qualityWaveform analysisCaptured Waveforms Displayed on Meter/GUI Comtrade - Standard IEEE File Format Waveform Captured On Threshold / Input Excess Dv/Dt Or Interruption Capture Trigger Waveform recording duration - 60 cycles Voltage Disturbance Wave Capture TriggerIndividual harmonics magnitudeTo 85thCurrent sensor input5AANSI % revenue accuracyC12.20 (0.2)Modification 3NonePower supply voltage100-240 V, 110-250 VdcEaton Corporation plc Eaton House30 Pembroke Road Dublin 4, Ireland © 2023 Eaton. All Rights Reserved. Eaton is a registered trademark.All other trademarks areproperty of their respectiveowners./socialmedia。