max348xe
MEMORY存储芯片MAX3485EESA中文规格书
General 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 SwitchingFeatures●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 forDriver Overload ProtectionOrdering Information continued at end of data sheet.PART TEMP . RANGE PIN-PACKAGE MAX3483E CSA 0°C to+70°C 8 SO MAX3483ECPA 0°C to+70°C 8 Plastic DIP MAX3483EESA -40°C to+85°C 8 SO MAX3483EEPA-40°C to+85°C8 Plastic DIPPART NUMBER GUARANTEED DATA RATE (Mbps)SUPPLY VOLTAGE(V)HALF/FULL DUPLEXSLEW-RATE LIMITEDDRIVER/RECEIVER ENABLESHUTDOWN CURRENT (nA)±15kV ESD PROTECTIONPIN COUNTMAX3483E 0.25 3.0 to 3.6Half Yes Yes 2Yes 8MAX3485E 12Half No Yes 2Yes 8MAX3486E 2.5Half Yes Yes 2Yes 8MAX3488E 0.25Full Yes No —Yes 8MAX3490E 12Full No No —Yes 8MAX3491E12FullNoYes2Yes14MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected,12Mbps and Slew-Rate-Limited True RS-485/RS-422 TransceiversSelector GuideOrdering Information(V CC = +3.3V ±0.3V, T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.)PARAMETERSYMBOL CONDITIONSMIN TYPMAXUNITSDifferential Driver Output V ODR L = 100Ω (RS-422), Figure 4 2.0VR L = 54Ω (RS-485), Figure 41.5R L = 60Ω (RS-485), V CC = 3.3V, Figure 51.5Change in Magnitude of Driver Differential Output Voltage for Complementary Output States (Note 1)∆V ODR L = 54Ω or 100Ω, Figure 40.2VDriver Common-Mode Output VoltageV OC R L = 54Ω or 100Ω, Figure 43VChange in Magnitude ofCommon-Mode Output Voltage (Note 1)∆V OC R L = 54Ω or 100Ω, Figure 40.2V Input High Voltage V IH DE, DI, RE 2.0VInput Low Voltage V IL DE, DI, RE 0.8V Logic Input Current I IN1DE, DI, RE ±2μA Input Current (A, B)I IN2DE = 0V,V CC = 0V or 3.6VV IN = 12V 1.0mA V IN = -7V -0.8Output Leakage (Y , Z)I O DE = 0V, RE = 0V,V CC = 0V or 3.6V, MAX3491E V OUT = 12V 20μA V OUT = -7V -20Output Leakage (Y , Z)in Shutdown ModeI O DE = 0V, RE = V CC ,V CC = 0V or 3.6V, MAX3491E V OUT = 12V 1μA V OUT = -7V-1Receiver Differential Threshold VoltageV TH -7V ≤ V CM ≤ 12V -0.20.2V Receiver Input Hysteresis ∆V TH V CM = 0V50mV Receiver Output High Voltage V OH I OUT = -1.5mA, V ID = 200mV, Figure 6V CC - 0.4VReceiver Output Low Voltage V OL I OUT = 2.5mA, V ID = 200mV, Figure 60.4V Three-State (High Impedance)Output Current at Receiver I OZR V CC = 3.6V, 0V ≤ V OUT ≤ V CC ±1μA Receiver Input Resistance R IN -7V ≤ V CM ≤ 12V12kΩSupply Voltage RangeV CC3.0 3.6VMAX3486E/MAX3488E/MAX3490E/MAX3491E12Mbps and Slew-Rate-Limited True RS-485/RS-422 TransceiversDC Electrical Characteristics(V CC = +3.3V ±0.3V, T A = T MIN to T MAX, unless otherwise noted. Typical values are at T A = +25°C)PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSSupply Current I CC No load,DI = 0 or V CCDE = V CC, RE = 0 or V CC 1.1 2.2mA DE = 0V, RE = 00.95 1.9Supply Current in Shutdown Mode I SHDN DE = 0, RE = V CC, DI = V CC or 00.0021µADriver Short-Circuit Output Current I OSDV OUT = -7V-250mA V OUT = 12V250Receiver Short-Circuit OutputCurrentI OSR0 ≤ V RO ≤ V CC±8±60mAESD Protection for Y, Z, A, B IEC 1000-4-2 Air Discharge±15kV IEC 1000-4-2 Contact Discharge (MAX3483E,MAX3485E, MAX3486E, MAX3491E)±8IEC 1000-4-2 Contact Discharge (MAX3490E,MAX3488E)*±6Human Body Model±15MAX3486E/MAX3488E/ MAX3490E/MAX3491E12Mbps and Slew-Rate-Limited True RS-485/RS-422 TransceiversDC Electrical Characteristics (continued)(V CC = +3.3V, T A = +25°C)(V CC = +3.3V, T A = +25°C.)PARAMETERSYMBOLCONDITIONS MIN TYPMAXUNITS Maximum Data Rate2.5Mbps Driver Differential Output Delayt DD R L = 60Ω, Figure 7204270ns Driver Differential Output Transition Time t TD R L = 60Ω, Figure 7152860ns Driver Propagation Delay, Low-to-High Level t PLH R L = 27Ω, Figure 8204275ns Driver Propagation Delay, High-to-Low Level t PHL R L = 27Ω, Figure 8204275ns |t PLH - t PHL | Driver Propagation Delay Skew (Note 2)t PDSR L = 27Ω, Figure 8-6±12ns DRIVER-OUTPUT ENABLE/DISABLE TIMES Driver Output Enable Time to Low Level t PZL R L = 110Ω, Figure 1052100ns Driver Output Enable Time to High Level t PZH R L = 110Ω, Figure 952100ns Driver Output Disable Time from High Level t PHZ R L = 110Ω, Figure 94080ns Driver Output Disable Time from Low Levelt PLZ R L = 110Ω, Figure 104080ns Driver Output Enable Time from Shutdown to Low Level t PSL R L = 110Ω, Figure 107001000ns Driver Output Enable Time from Shutdown to High Levelt PSH R L = 110Ω, Figure 97001000nsPARAMETERSYMBOLCONDITIONSMIN TYPMAXUNITS Maximum Data Rate250kbps Driver Differential Output Delayt DD R L = 60Ω, Figure 76009001400ns Driver Differential Output Transition Time t TD R L = 60Ω, Figure 74007401200ns Driver Propagation Delay, Low-to-High Level t PLH R L = 27Ω, Figure 87009301500ns Driver Propagation Delay, High-to-Low Level t PHL R L = 27Ω, Figure 87009301500ns |t PLH - t PHL | Driver Propagation Delay Skew (Note 2)t PDS R L = 27Ω, Figure 8±50ns DRIVER-OUTPUT ENABLE/DISABLE TIMES (MAX3483E only)Driver-Output Enable Time to Low Level t PZL R L = 110Ω, Figure 109001300ns Driver-Output Enable Time to High Level t PZH R L = 110Ω, Figure 9600800ns Driver-Output Disable Time from High Level t PHZ R L = 110Ω, Figure 95080ns Driver-Output Disable Time from Low Levelt PLZ R L = 110Ω, Figure 105080ns Driver-Output Enable Time from Shutdown to Low Level t PSL R L = 110Ω, Figure 10 1.9 2.7µs Driver-Output Enable Time from Shutdown to High Levelt PSHR L = 110Ω, Figure 92.23.0µsMAX3486E/MAX3488E/MAX3490E/MAX3491E12Mbps and Slew-Rate-Limited True RS-485/RS-422 TransceiversDriver Switching Characteristics—MAX3483E/MAX3488EDriver Switching Characteristics—MAX3486EMAX3483E/MAX3485E/ MAX3486E/MAX3488E/ MAX3490E/MAX3491E 3.3V-Powered, ±15kV ESD-Protected,12Mbps and Slew-Rate-LimitedTrue RS-485/RS-422 Transceivers。
MAX3490EESA+中文资料
General 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 protect-ed 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 guarantees 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.ApplicationsTelecommunicationsIndustrial-Control Local Area Networks Transceivers for EMI-Sensitive Applications Integrated Services Digital Networks Packet SwitchingFeatureso 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 o Operate from a Single +3.3V Supply—No Charge Pump Required o Interoperable with +5V Logic o Guaranteed 12Mbps Data Rate (MAX3485E/MAX3490E/MAX3491E)o Slew-Rate Limited for Errorless Data Transmission (MAX3483E/MAX3488E) o 2nA Low-Current Shutdown Mode(MAX3483E/MAX3485E/MAX3486E/MAX3491E)o -7V to +12V Common-Mode Input Voltage Range o Full-Duplex and Half-Duplex Versions Available o Industry-Standard 75176 Pinout (MAX3483E/MAX3485E/MAX3486E)o Current-Limiting and Thermal Shutdown for Driver Overload ProtectionMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers________________________________________________________________Maxim Integrated Products119-1474; Rev 0; 4/99Selector GuideOrdering InformationOrdering Information continued at end of data sheet.For free samples & the latest literature: , or phone 1-800-998-8800.For small orders, phone 1-800-835-8769.M A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceiversABSOLUTE MAXIMUM RATINGSDC ELECTRICAL CHARACTERISTICS(V = +3.3V ±0.3V, T = T to T , unless otherwise noted. Typical values are at T = +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.Supply Voltage (V CC ).............................................................+7V Control Input Voltage (RE , DE).................................-0.3V to +7V Driver Input Voltage (DI)...........................................-0.3V to +7V Driver Output Voltage (A, B, Y, Z).......................-7.5V to +12.5V Receiver Input Voltage (A, B)..............................-7.5V to +12.5V Receiver Output Voltage (RO)....................-0.3V to (V CC + 0.3V)Continuous Power Dissipation (T A = +70°C)8-Pin SO (derate 5.88mW/°C above +70°C)..................471mW 8-Pin Plastic DIP (derate 9.09mW/°C above +70°C).....727mW14-Pin SO (derate 8.33mW/°C above +70°C)................667mW 14-Pin Plastic DIP (derate 10mW/°C above +70°C)......800mW Operating Temperature RangesMAX34_ _ EC_ _...................................................0°C to +70°C MAX34_ _ EE_ _.................................................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10sec).............................+300°CMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceiversDC ELECTRICAL CHARACTERISTICS (continued)(V CC = +3.3V ±0.3V, T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.)DRIVER SWITCHING CHARACTERISTICS—MAX3485E/MAX3490E/MAX3491E(V = +3.3V, T = +25°C.)DRIVER SWITCHING CHARACTERISTICS—MAX3486E(V = +3.3V, T = +25°C.)*MAX3488E and MAX3491E will be compliant to ±8kV per IEC 1000-4-2 Contact Discharge by September 1999.M A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers4_______________________________________________________________________________________DRIVER SWITCHING CHARACTERISTICS—MAX3483E/MAX3488E(V CC = +3.3V, T A = +25°C.)RECEIVER SWITCHING CHARACTERISTICS(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, thedevices are guaranteed not to enter shutdown. If the inputs are in this state for at least 300ns, the devices are guaranteed to have entered shutdown. See Low-Power Shutdown Mode section.MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers_______________________________________________________________________________________5Typical Operating Characteristics(V CC = +3.3V, T A = +25°C, unless otherwise noted.)252015105000.51.01.52.02.53.53.0OUTPUT CURRENT vs.RECEIVER OUTPUT LOW VOLTAGEM A X 3483E -01OUTPUT LOW VOLTAGE (V)O U T P U T C U R R E N T (m A )-20-18-16-14-12-10-8-6-4-2000.51.01.52.02.53.53.0OUTPUT CURRENT vs.RECEIVER OUTPUT HIGH VOLTAGEM A X 3483E -02OUTPUT HIGH VOLTAGE (V)O U T P U T C U R R E N T (m A )3.003.053.103.153.203.253.30-40-20020406010080RECEIVER OUTPUT HIGH VOLTAGEvs. TEMPERATURETEMPERATURE (°C)O U T P U T H I G H V O L T A G E (V )00.10.20.30.40.50.60.70.8-40-2020406010080RECEIVER OUTPUT LOW VOLTAGEvs. TEMPERATURETEMPERATURE (°C)O U T P U T L O W V O L T A G E (V )2505075100125150175024681012OUTPUT CURRENT vs.DRIVER OUTPUT LOW VOLTAGEM A X 3483E -07OUTPUT LOW VOLTAGE (V)O U T P U T C U R R E N T (m A )100908070605040302010000.5 1.0 1.5 2.0 2.5 3.53.0DRIVER OUTPUT CURRENT vs.DIFFERENTIAL OUTPUT VOLTAGEM A X 3483E -05DIFFERENTIAL OUTPUT VOLTAGE (V)O U T P U T C U R R E N T (m A )1.61.71.81.92.02.12.22.32.42.62.5-40-20020406010080DRIVER 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 )-100-80-60-40-20543210-7-6-3-4-5-2-1OUTPUT CURRENT vs.DRIVER OUTPUT HIGH VOLTAGEM A X 3483E -08OUTPUT HIGH VOLTAGE (V)O U T P U T C U R R E N T (m A )M A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers0.80.70.91.01.11.2-40-2020406010080SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (m A )Typical Operating Characteristics (continued)(V CC = +3.3V, T A = +25°C, unless otherwise noted.)0102030405060708010090-40-2020406010080SHUTDOWN CURRENT vs. TEMPERATUREM A X 3483E -10TEMPERATURE (°C)S H U T D O W N C U R R E N T (n A )Pin DescriptionMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers_______________________________________________________________________________________7Figure 2. MAX3488E/MAX3490E Pin Configuration and Typical Operating CircuitFigure 3. MAX3491E Pin Configuration and Typical Operating CircuitFigure 1. MAX3483E/MAX3485E/MAX3486E Pin Configuration and Typical Operating CircuitM A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers8_______________________________________________________________________________________Figure 4. Driver V OD and V OC Figure 7. Driver Differential Output Delay and Transition TimesFigure 6. Receiver V OH and V OLFigure 5. Driver V OD with Varying Common-Mode VoltageMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers_______________________________________________________________________________________9Figure 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 )M A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers10______________________________________________________________________________________Figure 11. Receiver Propagation DelayFigure 12. Receiver Enable and Disable TimesNote 4: The input pulse is supplied by a generator with the following characteristics: f = 250kHz, 50% duty cycle, t r ≤6.0ns, Z O = 50Ω.Note 5: C L includes probe and stray capacitance._____________________Function TablesDevices with Receiver/Driver Enable(MAX3483E/MAX3485E/MAX3486E/MAX3491E)Table 1. Transmitting* B and A outputs are Z and Y, respectively, for full-duplex part (MAX3491E).X = Don’t care; High-Z = High impedanceTable 2. Receiving* DE is a “don’t care” (x) for the full-duplex part (MAX3491E).X = Don’t care; High-Z = High impedanceDevices without Receiver/Driver Enable(MAX3488E/MAX3490E)Table 3. TransmittingTable 4. Receiving___________Applications InformationThe MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E are low-power transceivers for RS-485 and RS-422 communications. The MAX3483E and MAX3488E can transmit and receive at data rates up to 250kbps, the MAX3486E at up to 2.5Mbps, and the MAX3485E/MAX3490E/MAX3491E at up to 12Mbps. The MAX3488E/MAX3490E/MAX3491E are full-duplex trans-ceivers, while the MAX3483E/MAX3485E/MAX3486E are half-duplex. Driver Enable (DE) and Receiver Enable (RE ) pins are included on the MAX3483E/MAX3485E/MAX3486E/MAX3491E. When disabled, the driver and receiver outputs are high impedance.Reduced EMI and Reflections (MAX3483E/MAX3486E/MAX3488E)The MAX3483E/MAX3488E are slew-rate limited, mini-mizing EMI and reducing reflections caused by improp-erly terminated cables. Figure 13 shows the driver output waveform of a MAX3485E/MAX3490E/MAX3491E transmitting a 125kHz signal, as well as the Fourier analysis of that waveform. High-frequency harmonics with large amplitudes are evident. Figure 14 shows the same information, but for the slew-rate-limited MAX3483E/MAX3488E transmitting the same signal. The high-frequency harmonics have much lower amplitudes,and the potential for EMI is significantly reduced.Low-Power Shutdown Mode(MAX3483E/MAX3485E/MAX3486E/MAX3491E)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 (high impedance). In shutdown, the devices typically draw only 2nA of supply current.For these devices, the t PSH and t PSL enable times assume the part was in the low-power shutdown mode;the t PZH and t PZL enable times assume the receiver or driver was disabled, but the part was not shut down.MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers______________________________________________________________________________________11INPUTS OUTPUT A, B RO ≥+0.2V 1≤-0.2V 0Inputs Open1INPUT OUTPUTS DI Z Y 101015MHz 500kHz/div 05MHz500kHz/div Figure 13. Driver Output Waveform and FFT Plot of MAX3485E/MAX3490E/MAX3491E Transmitting a 125kHz Signal Figure 14. Driver Output Waveform and FFT Plot of MAX3483E/ MAX3488E Transmitting a 125kHz SignalM A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers12______________________________________________________________________________________Figure 17. MAX3483E/MAX3488E Driver Propagation Delay Figure 19. MAX3483E/MAX3488E System Differential Voltage at 125kHz Driving 4000 Feet of Cable Figure 20. MAX3485E/MAX3490E/MAX3491E System Differential Voltage at 125kHz Driving 4000 Feet of CableDriver-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 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 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 Rate The 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 120Ωloads.For faster data rate transmission, please consult the fac-tory.±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 transmitter outputs and receiver inputs of this product family are characterized for protection to the following limits:1)±15kV using the Human Body Model2)±8kV using the Contact-Discharge method specifiedin 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 inter-est, which is then discharged into the test device through a 1.5kΩresistor.IEC 1000-4-2 The 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 current in IEC 1000-4-2, because series resistance is lower in the IEC 1000-4-2 model. Hence, the ESD with-stand 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 4 ESD contact-discharge test.Figure 21. Line Repeater for MAX3488E/MAX3490E/MAX3491EMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers ______________________________________________________________________________________13M A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491EThe 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 when I/O pins are contacted by handling equipment during test and assembly. Of course, all pins require this protection, not just RS-485 inputs and outputs.Typical ApplicationsThe MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E transceivers are designed for bidirectional data communications on multipoint bus transmission lines. Figures 24 and 25 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 21.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 possible. The slew-rate-limited MAX3483E/MAX3488E and the partially slew-rate-limited MAX3486E are more tolerant of imperfect termination.3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers14______________________________________________________________________________________Figure 22a. Human Body ESD Test ModelFigure 22b. Human Body Current WaveformFigure 23a. IEC 1000-4-2 ESD Test ModelFigure 23b. IEC 1000-4-2 ESD Generator Current WaveformMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers______________________________________________________________________________________15Figure 25. MAX3488E/MAX3490E/MAX3491E Full-Duplex RS-485 NetworkFigure 24. MAX3483E/MAX3485E/MAX3486E Typical RS-485 NetworkM A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceiversTRANSISTOR COUNT: 761Chip InformationOrdering Information (continued)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©1999 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.。
MAX3490摘出资料(部分中文)
MAX3488, MAX3490，MAX3491 功能，全双工通信，而 MAX3483, MAX3485, MAX3486是专为半双工通信。
单一的电源供应，没有电荷注入；具有+ 5V 逻辑电源互操作；最大偏斜为 8ns ； 2ns 低电流掉电模式；共模输入电压范围：—7〜+ 12V ,总线上允许多达 32个收发器；全双工和半双工版本；具有电流限制和热 关机驱动器过载保护驱动器具有短路电流限制和对功耗过大的保护，热关断电路，驱动器输岀置于高阻抗状态。
接收器输入具 有故障安全功能，保证逻辑高输岀，如果两个输入端开路。
选择MAX3490做RS-422,下图为 MAX3490引脚图1 ——VCC2―― RO 接收器输出 3―― DI 驱动器输入 4 ——GND 5 ---- Y 同相驱动器输出 6 ---- Z 反相驱动器输出 7 ---- B反相接收器输入8——A 同相接收器输入保证数据传输速率（Mbps ） 10电源电压（V ） to 半/全双工 全双工摆率限制 无 驱动器/接收器使 无 关断电流（NA ）关断时无引脚数8频率大，高频谐波明显MAX3490没有接收器发送器使能，控制逻辑如下图Dences 宙Rhouf Receiver/Driver Enable（MAX3488/MAX349a}T^ble 3. Transmitting T^able 4. ReceivingMAX3490 （无RE 、DE 引脚）绝对最大额定值如下图:IN^UTOUTPUTSDI zY 1 D 1 □1INPUTSOUTPUTA. 6 RO *D.2V1 <-a.2v0 Inputs Open1□IP/SOE L叵叵DABSOLUTE MAXIMUM RATINGSS U P P 卜F \ 01 ^3 9 e l\/ kill ■ ■ ■ ■ ■■!■■■■■■ iri ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■■ ■ ■ ■ ■ ■ i ■ ■ ■ r ■ ■ ■ ■ ■ ■ ■Control IrpiJ ValLage (RE, D£) ............... .......... ............... -0.3V ta 7V□rtvsr Inpul Voltage (6l).............. .......... .......... ............... -0.3Vtn 7VOnvar Output VcItaQ* (A,気V, ZX - ......................... -7J5V to12.SVftccer^CF Input VaKagc |A, B) . -7.5V to )2 5VReceiver Ojtput Voltage (RO) . . -O.3Vto (Vcc * 0 3V)Gontinucus Power g$ipmTk?n (T R= +70芒|各Pin Pi/Mc DIP 忖申rate 9 09mWU above +70© 72?mW8-Pin SO (<1HW 5 aarrrtVy «bove +7C P C), 471mW14-Rn Plastic DlP(de<m© 10mW fl C above +70忙》... HOOtrMf14-Rn SO (deia1^ fl.SSmW.^C abaw +70*C> __________ UUJllMfOperating Temperalur?MAXU C .............. ......... *........ ... ..................... -.Ot：to +7[TCMAX3d_ _E__”…lh.. “一,. ,.H.…““-“,-H.⑷乜B +85\：Storage Temperafur? Range lo +16[yCbead Tempeiature [wldering lOlMC)..................................... +XD*CMAX3490驱动器的开关特性如下图:DRIVER SWITCHING CHARACTERISTICS-MAX3465h MAX14$0, and MAX3491ri^E：» 3.3M a T*w *25*CJPARAMtFER CONCilTICNS m TVP MA 9(UNITSDrrwf OHtreftfiii OdljMjt Del叩g■ Sdll, Figure 7 122M mDrvcr Wfe-oEiii Ckrlp ui T M7»C r Time hno良L * fiOtl, Flpm 71&25mEtr p临他n M■丫LCfflMCHHiah Lrvtl IpiLM R L * 37(1. F4l/*a T2235m轉、ion Delay Hl0hi&-Lew Leveli IpML R. - ZTflFiflWWE■Jr22 35tp L n - iPHitl □越g*曲m Dtt&Ff吕的却iH^ie S- IPDS R.fc• 27n, FipL<eS E mDRIVER OUTPUT ENABLEJOIS^BLE TIMES {IWS-iflS'IMLW3-431 聞切Dmw CXJtput tnable r me I Q L OW LE^el tfZL Ri= 110SL f^FLFa 10 45 M OEDiwci" OulpiJl EiwN? Trne tg High Len el S FZH Ri ■ 110(1 钿ure $ 45raDrw CMp讥04»^le Time tom Migih Level fi t* 11(X1. F»flL*t940 to POriw D・*l・ Tim from LwLwi tpLE R L* 11IMI. i&40 BO mDTM< dip Lit Errtb^A Tiffii Au墟电叭旳Lx L#v4l tm Rl ■匚如i 10<8W gm 他Qrta&r ErrtBifi Titre frw 电靜©询|a H(；h 4PCH R; - 1inni FigiLiraS®o r»MAX3490CPA(TCto +70'Q8 Ptasttc DIPMAX349OCSA(TCt口+7D B C\8 SOMAX3490C/D crcto+70e c \Dice'MAX349OEPA-4(rc to +85X8 Plastic DIPMAX349OESA■40X10+9598 SOMAX3490引脚配置与典型工作电路，如下图|l巒4e 2 MAA J4ML JWAJC3啲Pin 8 两#挪询事呵Typ"C^ uftMOTE AEANODE O 8LXF砂*师悶ZKSQW诂沖盟F训卜皿咻斥$钵自Ncrv^OfU MAX3490封装尺寸L -15^ Plastic DIPPLASTIC DU AL-IN-LINE PACKAGE(0.300 in.)DIM [HOMES MLLlWETESS MIN MAA MIN MAXA a 200A1ocn&-■"20 12& C 175 3104-iS *3 0D5& Q0» 1.402W0.01S a 022 041 OKoo^ 1 MC DQOB0 0120200 30 &1D0Q&0 09001328E0.300 0 925 A2A E10咖0 310dia7VT e OJOO■■eA D.3H)■*tB Q4P0 10 16 L 0 IU a iso 2923J1 PINSMCHES MJJME1TER3-MN NUM MNI MAXa 0 3430 w BM 891 0140^3513-6719-43 ET lir o.-«Q -B51: 911&.43 010MBS 0i1522 4B 23.24 020 101S104535742454□24 1 14H2B52S DE37 13。
MAX485EEPA+中文资料
14-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 Ranges MAX4_ _C_ _/MAX1487EC_ A .............................0°C to +70°C MAX4_ _E_ _/MAX1487EE_ A...........................-40°C to +85°C StorageБайду номын сангаасTemperature Range .............................-65°C to +160°C Lead Temperature (soldering, 10sec) .............................+300°C
Receiver Output Voltage (RO)....................-0.5V to (VCC + 0.5V)
Continuous Power Dissipation (TA = +70°C)
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) ....727mW
Ordering Information
PART MAX481ECPA MAX481ECSA MAX481EEPA MAX481EESA MAX483ECPA MAX483ECSA MAX483EEPA MAX483EESA
max3485中文资料
max3485中文资料max3485eesa + T概述Max3485eesa + T是3.3V电源±15kV ESD保护，真正的RS485 / RS422收发器，采用8引脚nsoic封装。
该低功耗收发器包含一个驱动器和一个接收器。
max3485e传输速率高达15Mbps。
它具有增强的静电保护。
所有发送器输出和接收器输入均具有±15kV保护，并通过IEC 1000-4-2气隙放电；±8Kv保护是通过IEC 1000-4-2接触放电，±15kV保护是通过人体模型。
驱动器受到短路电流的限制，并通过将驱动器输出置于高阻抗状态的热关断电路来防止过多的功耗。
接收器输入具有故障安全功能，如果两个输入均打开，则提供逻辑高电平输出。
Max3485e适用于EMI敏感应用，集成服务，数字网络和数据包交换电源电压范围：3V至3.6V工作温度范围-40°C至85°C半双工通讯该操作由单个+ 3.3V电源供电，无电荷泵兼容+ 5V逻辑2Na小电流关闭模式共模输入电压范围：-7V至+ 12V工业标准75176引脚输出驱动器/接收器启用功能工业控制LAN，ISDN，低功耗RS-485 / RS-422收发器;分组交换;电信;用于EMI敏感应用的收发器Max3483，max3485，max3486，max3488，max3490和max3491是用于RS-485和RS-422通信的3.3V低功耗收发器，每个收发器都有一个驱动器和一个接收器。
Max3483和max3488具有有限速率驱动器，可以降低EMI并减少由于端子匹配电缆不合适而引起的反射，从而实现高达250kbps的无错误数据传输。
由于其有限的摆幅速率，Max3486可以实现最大2.5mbps 的传输速率。
Max3485，max3490和max3491可以实现高达10Mbps的传输速率。
驱动器具有短路电流限制，并且可以通过热关断电路将驱动器的输出设置为高阻状态，以防止过多的功率损耗。
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.。
MAX488中文资料
元器件交易网
±15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 Transceivers
MAX481E/MAX483E/MAX485E/MAOLUTE MAXIMUM RATINGS
____________________________Features
o ESD Protection: ±15kV—Human Body Model o Slew-Rate Limited for Error-Free Data Transmission (MAX483E/487E/488E/489E) o Low Quiescent Current: 120µA (MAX483E/487E/488E/489E) 230µA (MAX1487E) 300µA (MAX481E/485E/490E/491E) o -7V to +12V Common-Mode Input Voltage Range o Three-State Outputs o 30ns Propagation Delays, 5ns Skew (MAX481E/485E/490E/491E/1487E) o Full-Duplex and Half-Duplex Versions Available o Allows up to 128 Transceivers on the Bus (MAX487E/MAX1487E) o Current Limiting and Thermal Shutdown for Driver Overload Protection
Ordering Information continued on last page.
______________________________________________________________Selection Table
max3485ed工作原理
max3485ed工作原理
MAX3485ED是一种RS-485/RS-422收发器芯片，它主要用于工业控制系统、远程监控和通信设备等领域。
它具有高抗干扰能力和高速传输的特点，下面我将从几个角度来解释MAX3485ED的工作原理。
1. 工作模式：
MAX3485ED可以同时用作RS-485和RS-422接口。
RS-485是一种差分信号传输标准，可以实现多点通信，而RS-422是一种差分信号传输标准，用于点对点通信。
MAX3485ED可以根据需要配置为这两种模式之一。
2. 差分信号传输：
MAX3485ED的工作原理基于差分信号传输。
差分信号传输利用两根导线，分别传输正负两个相位的信号。
这种传输方式可以有效抵抗电磁干扰，提高信号的抗干扰能力和传输距离。
3. 驱动能力：
MAX3485ED具有较强的驱动能力，可以驱动较长的总线长度，同时支持高达250kbps的数据传输速率。
它的驱动能力和高速传输性能使其在工业控制系统中得到广泛应用。
4. 保护功能：
MAX3485ED内置了过压保护和短路保护电路，可以有效保护芯片不受外部干扰和损坏。
这些保护功能提高了芯片的稳定性和可靠性。
5. 工作电压范围：
MAX3485ED可以在3.3V或5V的工作电压下正常工作，这使得它可以适应不同的系统设计需求。
综上所述，MAX3485ED作为RS-485/RS-422收发器芯片，通过差分信号传输实现高速、抗干扰的数据通信，具有较强的驱动能力和保护功能，适用于工业控制系统等领域。
希望以上信息能够全面地回答你的问题。
【小付出,大回报】 Canon PIXMA MX348喷墨多功能一体机
全部测试耗时
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MAX3490EESA中文资料
General 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 protect-ed 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 guarantees 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.ApplicationsTelecommunicationsIndustrial-Control Local Area Networks Transceivers for EMI-Sensitive Applications Integrated Services Digital Networks Packet SwitchingFeatureso 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 o Operate from a Single +3.3V Supply—No Charge Pump Required o Interoperable with +5V Logic o Guaranteed 12Mbps Data Rate (MAX3485E/MAX3490E/MAX3491E)o Slew-Rate Limited for Errorless Data Transmission (MAX3483E/MAX3488E) o 2nA Low-Current Shutdown Mode(MAX3483E/MAX3485E/MAX3486E/MAX3491E)o -7V to +12V Common-Mode Input Voltage Range o Full-Duplex and Half-Duplex Versions Available o Industry-Standard 75176 Pinout (MAX3483E/MAX3485E/MAX3486E)o Current-Limiting and Thermal Shutdown for Driver Overload ProtectionMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers________________________________________________________________Maxim Integrated Products119-1474; Rev 0; 4/99Selector GuideOrdering InformationOrdering Information continued at end of data sheet.For free samples & the latest literature: , or phone 1-800-998-8800.For small orders, phone 1-800-835-8769.M A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceiversABSOLUTE MAXIMUM RATINGSDC ELECTRICAL CHARACTERISTICS(V = +3.3V ±0.3V, T = T to T , unless otherwise noted. Typical values are at T = +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.Supply Voltage (V CC ).............................................................+7V Control Input Voltage (RE , DE).................................-0.3V to +7V Driver Input Voltage (DI)...........................................-0.3V to +7V Driver Output Voltage (A, B, Y, Z).......................-7.5V to +12.5V Receiver Input Voltage (A, B)..............................-7.5V to +12.5V Receiver Output Voltage (RO)....................-0.3V to (V CC + 0.3V)Continuous Power Dissipation (T A = +70°C)8-Pin SO (derate 5.88mW/°C above +70°C)..................471mW 8-Pin Plastic DIP (derate 9.09mW/°C above +70°C).....727mW14-Pin SO (derate 8.33mW/°C above +70°C)................667mW 14-Pin Plastic DIP (derate 10mW/°C above +70°C)......800mW Operating Temperature RangesMAX34_ _ EC_ _...................................................0°C to +70°C MAX34_ _ EE_ _.................................................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10sec).............................+300°CMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceiversDC ELECTRICAL CHARACTERISTICS (continued)(V CC = +3.3V ±0.3V, T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.)DRIVER SWITCHING CHARACTERISTICS—MAX3485E/MAX3490E/MAX3491E(V = +3.3V, T = +25°C.)DRIVER SWITCHING CHARACTERISTICS—MAX3486E(V = +3.3V, T = +25°C.)*MAX3488E and MAX3491E will be compliant to ±8kV per IEC 1000-4-2 Contact Discharge by September 1999.M A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers4_______________________________________________________________________________________DRIVER SWITCHING CHARACTERISTICS—MAX3483E/MAX3488E(V CC = +3.3V, T A = +25°C.)RECEIVER SWITCHING CHARACTERISTICS(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, thedevices are guaranteed not to enter shutdown. If the inputs are in this state for at least 300ns, the devices are guaranteed to have entered shutdown. See Low-Power Shutdown Mode section.MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers_______________________________________________________________________________________5Typical Operating Characteristics(V CC = +3.3V, T A = +25°C, unless otherwise noted.)252015105000.51.01.52.02.53.53.0OUTPUT CURRENT vs.RECEIVER OUTPUT LOW VOLTAGEM A X 3483E -01OUTPUT LOW VOLTAGE (V)O U T P U T C U R R E N T (m A )-20-18-16-14-12-10-8-6-4-2000.51.01.52.02.53.53.0OUTPUT CURRENT vs.RECEIVER OUTPUT HIGH VOLTAGEM A X 3483E -02OUTPUT HIGH VOLTAGE (V)O U T P U T C U R R E N T (m A )3.003.053.103.153.203.253.30-40-20020406010080RECEIVER OUTPUT HIGH VOLTAGEvs. TEMPERATURETEMPERATURE (°C)O U T P U T H I G H V O L T A G E (V )00.10.20.30.40.50.60.70.8-40-2020406010080RECEIVER OUTPUT LOW VOLTAGEvs. TEMPERATURETEMPERATURE (°C)O U T P U T L O W V O L T A G E (V )2505075100125150175024681012OUTPUT CURRENT vs.DRIVER OUTPUT LOW VOLTAGEM A X 3483E -07OUTPUT LOW VOLTAGE (V)O U T P U T C U R R E N T (m A )100908070605040302010000.5 1.0 1.5 2.0 2.5 3.53.0DRIVER OUTPUT CURRENT vs.DIFFERENTIAL OUTPUT VOLTAGEM A X 3483E -05DIFFERENTIAL OUTPUT VOLTAGE (V)O U T P U T C U R R E N T (m A )1.61.71.81.92.02.12.22.32.42.62.5-40-20020406010080DRIVER 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 )-100-80-60-40-20543210-7-6-3-4-5-2-1OUTPUT CURRENT vs.DRIVER OUTPUT HIGH VOLTAGEM A X 3483E -08OUTPUT HIGH VOLTAGE (V)O U T P U T C U R R E N T (m A )M A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers0.80.70.91.01.11.2-40-2020406010080SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (m A )Typical Operating Characteristics (continued)(V CC = +3.3V, T A = +25°C, unless otherwise noted.)0102030405060708010090-40-2020406010080SHUTDOWN CURRENT vs. TEMPERATUREM A X 3483E -10TEMPERATURE (°C)S H U T D O W N C U R R E N T (n A )Pin DescriptionMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers_______________________________________________________________________________________7Figure 2. MAX3488E/MAX3490E Pin Configuration and Typical Operating CircuitFigure 3. MAX3491E Pin Configuration and Typical Operating CircuitFigure 1. MAX3483E/MAX3485E/MAX3486E Pin Configuration and Typical Operating CircuitM A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers8_______________________________________________________________________________________Figure 4. Driver V OD and V OC Figure 7. Driver Differential Output Delay and Transition TimesFigure 6. Receiver V OH and V OLFigure 5. Driver V OD with Varying Common-Mode VoltageMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers_______________________________________________________________________________________9Figure 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 )M A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers10______________________________________________________________________________________Figure 11. Receiver Propagation DelayFigure 12. Receiver Enable and Disable TimesNote 4: The input pulse is supplied by a generator with the following characteristics: f = 250kHz, 50% duty cycle, t r ≤6.0ns, Z O = 50Ω.Note 5: C L includes probe and stray capacitance._____________________Function TablesDevices with Receiver/Driver Enable(MAX3483E/MAX3485E/MAX3486E/MAX3491E)Table 1. Transmitting* B and A outputs are Z and Y, respectively, for full-duplex part (MAX3491E).X = Don’t care; High-Z = High impedanceTable 2. Receiving* DE is a “don’t care” (x) for the full-duplex part (MAX3491E).X = Don’t care; High-Z = High impedanceDevices without Receiver/Driver Enable(MAX3488E/MAX3490E)Table 3. TransmittingTable 4. Receiving___________Applications InformationThe MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E are low-power transceivers for RS-485 and RS-422 communications. The MAX3483E and MAX3488E can transmit and receive at data rates up to 250kbps, the MAX3486E at up to 2.5Mbps, and the MAX3485E/MAX3490E/MAX3491E at up to 12Mbps. The MAX3488E/MAX3490E/MAX3491E are full-duplex trans-ceivers, while the MAX3483E/MAX3485E/MAX3486E are half-duplex. Driver Enable (DE) and Receiver Enable (RE ) pins are included on the MAX3483E/MAX3485E/MAX3486E/MAX3491E. When disabled, the driver and receiver outputs are high impedance.Reduced EMI and Reflections (MAX3483E/MAX3486E/MAX3488E)The MAX3483E/MAX3488E are slew-rate limited, mini-mizing EMI and reducing reflections caused by improp-erly terminated cables. Figure 13 shows the driver output waveform of a MAX3485E/MAX3490E/MAX3491E transmitting a 125kHz signal, as well as the Fourier analysis of that waveform. High-frequency harmonics with large amplitudes are evident. Figure 14 shows the same information, but for the slew-rate-limited MAX3483E/MAX3488E transmitting the same signal. The high-frequency harmonics have much lower amplitudes,and the potential for EMI is significantly reduced.Low-Power Shutdown Mode(MAX3483E/MAX3485E/MAX3486E/MAX3491E)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 (high impedance). In shutdown, the devices typically draw only 2nA of supply current.For these devices, the t PSH and t PSL enable times assume the part was in the low-power shutdown mode;the t PZH and t PZL enable times assume the receiver or driver was disabled, but the part was not shut down.MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers______________________________________________________________________________________11INPUTS OUTPUT A, B RO ≥+0.2V 1≤-0.2V 0Inputs Open1INPUT OUTPUTS DI Z Y 101015MHz 500kHz/div 05MHz500kHz/div Figure 13. Driver Output Waveform and FFT Plot of MAX3485E/MAX3490E/MAX3491E Transmitting a 125kHz Signal Figure 14. Driver Output Waveform and FFT Plot of MAX3483E/ MAX3488E Transmitting a 125kHz SignalM A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers12______________________________________________________________________________________Figure 17. MAX3483E/MAX3488E Driver Propagation Delay Figure 19. MAX3483E/MAX3488E System Differential Voltage at 125kHz Driving 4000 Feet of Cable Figure 20. MAX3485E/MAX3490E/MAX3491E System Differential Voltage at 125kHz Driving 4000 Feet of CableDriver-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 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 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 Rate The 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 120Ωloads.For faster data rate transmission, please consult the fac-tory.±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 transmitter outputs and receiver inputs of this product family are characterized for protection to the following limits:1)±15kV using the Human Body Model2)±8kV using the Contact-Discharge method specifiedin 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 inter-est, which is then discharged into the test device through a 1.5kΩresistor.IEC 1000-4-2 The 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 current in IEC 1000-4-2, because series resistance is lower in the IEC 1000-4-2 model. Hence, the ESD with-stand 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 4 ESD contact-discharge test.Figure 21. Line Repeater for MAX3488E/MAX3490E/MAX3491EMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers ______________________________________________________________________________________13M A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491EThe 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 when I/O pins are contacted by handling equipment during test and assembly. Of course, all pins require this protection, not just RS-485 inputs and outputs.Typical ApplicationsThe MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E transceivers are designed for bidirectional data communications on multipoint bus transmission lines. Figures 24 and 25 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 21.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 possible. The slew-rate-limited MAX3483E/MAX3488E and the partially slew-rate-limited MAX3486E are more tolerant of imperfect termination.3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers14______________________________________________________________________________________Figure 22a. Human Body ESD Test ModelFigure 22b. Human Body Current WaveformFigure 23a. IEC 1000-4-2 ESD Test ModelFigure 23b. IEC 1000-4-2 ESD Generator Current WaveformMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers______________________________________________________________________________________15Figure 25. MAX3488E/MAX3490E/MAX3491E Full-Duplex RS-485 NetworkFigure 24. MAX3483E/MAX3485E/MAX3486E Typical RS-485 NetworkM A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceiversTRANSISTOR COUNT: 761Chip InformationOrdering Information (continued)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©1999 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.。
max3485中文资料
max3485中文资料MAX3483，MAX3485，MAX3486，MAX3488，MAX3490以及MAX3491是用于RS-485与RS-422通信的3.3V，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。
MAX3483和MAX3488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。
MAX3486的驱动器摆率部分受限，可以实现最高2.5Mbps的传输速率。
MAX3485，MAX3490和MAX3491则可以实现最高10Mbps 的传输速率。
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。
特性●半双工●速率：10Mbps●限摆率：NO●接收允许控制：YES●关断电流：2nA●引脚数：8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120µA至500µA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。
采用单一电源+5 V工作，额定电流为300 μA，采用半双工通讯方式。
它完成将TTL电平转换为RS－485电平的功能。
MAX485芯片的结构和引脚都非常简单,内部含有一个驱动器和接收器。
RO和DI 端分别为接收器的输出和驱动器的输入端，与单片机连接时只需分别与单片机的RXD和TXD相连即可；/RE和DE端分别为接收和发送的使能端，当/RE为逻辑0时，器件处于接收状态；当DE为逻辑1时，器件处于发送状态，因为MAX485工作在半双工状态，所以只需用单片机的一个管脚控制这两个引脚即可；A端和B端分别为接收和发送的差分信号端,当A引脚的电平高于B时，代表发送的数据为1；当A的电平低于B端时，代表发送的数据为0。
MAX483E资料
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.。
MAX485ESA+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 .)。
MAX3490摘出资料(部分中文)
MAX3488，MAX3490，MAX3491功能，全双工通信，而MAX3483，MAX3485，MAX3486是专为半双工通信。
单一的电源供应，没有电荷注入；具有＋5V逻辑电源互操作；最大偏斜为8ns；2ns低电流掉电模式；共模输入电压范围：－7～＋12V，总线上允许多达32个收发器；全双工和半双工版本；具有电流限制和热关机驱动器过载保护
驱动器具有短路电流限制和对功耗过大的保护，热关断电路，驱动器输出置于高阻抗状态。
接收器输入具有故障安全功能，保证逻辑高输出，如果两个输入端开路。
选择MAX3490做RS-422，下图为MAX3490引脚图
1——VCC
2——RO 接收器输出
3——DI 驱动器输入
4——GND
5——Y 同相驱动器输出
6——Z 反相驱动器输出
7——B 反相接收器输入
8——A 同相接收器输入
保证数据传输速率（Mbps）10
电源电压（V）to
半/全双工全双工
摆率限制无
驱动器/接收器使无
关断电流（NA）关断时无
引脚数8
频率大，高频谐波明显
MAX3490没有接收器发送器使能，控制逻辑如下图
MAX3490（无RE、DE引脚）绝对最大额定值如下图：
MAX3490驱动器的开关特性如下图：
MAX3490型号及封装如下图
MAX3490引脚配置与典型工作电路，如下图
MAX3490封装尺寸。
max3485管脚定义
max3485管脚定义MAX3485是一款RS-485/RS-422收发器，它具有多种功能和特性，可以在工业自动化、通信领域等应用中发挥重要作用。
本文将围绕MAX3485的引脚定义展开介绍，以帮助读者更好地理解和应用该芯片。
1. DI（Driver Input）：该引脚是驱动器输入端，用于接收来自外部设备的数据输入。
MAX3485支持RS-485和RS-422两种通信标准，DI引脚可接收差分信号或单端信号。
2. DE（Driver Enable）：DE引脚是驱动器使能引脚，用于控制驱动器的开启和关闭。
当DE引脚处于高电平时，驱动器开启，开始发送数据；当DE引脚处于低电平时，驱动器关闭，停止发送数据。
3. RO（Receiver Output）：RO引脚是接收器输出端，用于输出接收到的数据。
MAX3485的RO引脚输出差分信号或单端信号，可连接到外部设备进行数据处理。
4. RE（Receiver Enable）：RE引脚是接收器使能引脚，用于控制接收器的开启和关闭。
当RE引脚处于高电平时，接收器开启，开始接收数据；当RE引脚处于低电平时，接收器关闭，停止接收数据。
5. A, B（Bus Terminals）：A和B引脚是总线终端，用于连接RS-485/RS-422总线。
A和B引脚是差分信号对，通过差分信号传输数据可以提高抗干扰能力和传输距离。
6. VCC（Power Supply）：VCC引脚是芯片的供电引脚，提供芯片所需的工作电压。
MAX3485的工作电压范围为3.0V至5.5V，可以适应不同的供电需求。
7. GND（Ground）：GND引脚是芯片的接地引脚，用于提供电路的共地。
MAX3485通过上述引脚实现了RS-485/RS-422通信的收发功能。
在实际应用中，我们可以根据具体需求来连接和配置这些引脚，以实现数据的可靠传输和通信的顺利进行。
在使用MAX3485时，需要注意以下几点：1. 引脚连接：将外部设备的数据输入引脚连接到DI引脚，将接收器输出引脚连接到RO引脚，将总线终端引脚连接到A和B引脚。
MAX3488ESA中文资料
_______________General Description ____________________________Features
The MAX3483, MAX3485, MAX3486, MAX3488, MAX3490, and MAX3491 are 3.3V, low-power transceivers for RS-485 and RS-422 communication. Each part contains one driver and one receiver. The MAX3483 and MAX3488 feature slew-rate-limited drivers that minimize EMI and reduce reflections caused by improperly terminated cables, allowing error-free data transmission at data rates up to 250kbps. The partially slew-rate-limited MAX3486 transmits up to 2.5Mbps. The MAX3485, MAX3490, and MAX3491 transmit at up to 10Mbps.
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.
MEMORY存储芯片MAX487EESA中文规格书
DC ELECTRICAL CHARACTERISTICS
(VCC = 5V ±5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
Differential Driver Output (no load)
14-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 Ranges MAX4_ _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) .........................nd 13, CL = 100pF, S2 closed tZL Figures 11 and 13, CL = 100pF, S1 closed tLZ Figures 11 and 13, CL = 15pF, S1 closed tHZ Figures 11 and 13, CL = 15pF, S2 closed
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General 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 protect-ed 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 guarantees 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.ApplicationsTelecommunicationsIndustrial-Control Local Area Networks Transceivers for EMI-Sensitive Applications Integrated Services Digital Networks Packet SwitchingFeatureso 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 o Operate from a Single +3.3V Supply—No Charge Pump Required o Interoperable with +5V Logic o Guaranteed 12Mbps Data Rate (MAX3485E/MAX3490E/MAX3491E)o Slew-Rate Limited for Errorless Data Transmission (MAX3483E/MAX3488E) o 2nA Low-Current Shutdown Mode(MAX3483E/MAX3485E/MAX3486E/MAX3491E)o -7V to +12V Common-Mode Input Voltage Range o Full-Duplex and Half-Duplex Versions Available o Industry-Standard 75176 Pinout (MAX3483E/MAX3485E/MAX3486E)o Current-Limiting and Thermal Shutdown for Driver Overload ProtectionMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers________________________________________________________________Maxim Integrated Products119-1474; Rev 0; 4/99Selector GuideOrdering InformationOrdering Information continued at end of data sheet.For free samples & the latest literature: , or phone 1-800-998-8800.For small orders, phone 1-800-835-8769.M A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceiversABSOLUTE MAXIMUM RATINGSDC ELECTRICAL CHARACTERISTICS(V = +3.3V ±0.3V, T = T to T , unless otherwise noted. Typical values are at T = +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.Supply Voltage (V CC ).............................................................+7V Control Input Voltage (RE , DE).................................-0.3V to +7V Driver Input Voltage (DI)...........................................-0.3V to +7V Driver Output Voltage (A, B, Y, Z).......................-7.5V to +12.5V Receiver Input Voltage (A, B)..............................-7.5V to +12.5V Receiver Output Voltage (RO)....................-0.3V to (V CC + 0.3V)Continuous Power Dissipation (T A = +70°C)8-Pin SO (derate 5.88mW/°C above +70°C)..................471mW 8-Pin Plastic DIP (derate 9.09mW/°C above +70°C).....727mW14-Pin SO (derate 8.33mW/°C above +70°C)................667mW 14-Pin Plastic DIP (derate 10mW/°C above +70°C)......800mW Operating Temperature RangesMAX34_ _ EC_ _...................................................0°C to +70°C MAX34_ _ EE_ _.................................................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10sec).............................+300°CMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceiversDC ELECTRICAL CHARACTERISTICS (continued)(V CC = +3.3V ±0.3V, T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.)DRIVER SWITCHING CHARACTERISTICS—MAX3485E/MAX3490E/MAX3491E(V = +3.3V, T = +25°C.)DRIVER SWITCHING CHARACTERISTICS—MAX3486E(V = +3.3V, T = +25°C.)*MAX3488E and MAX3491E will be compliant to ±8kV per IEC 1000-4-2 Contact Discharge by September 1999.M A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers4_______________________________________________________________________________________DRIVER SWITCHING CHARACTERISTICS—MAX3483E/MAX3488E(V CC = +3.3V, T A = +25°C.)RECEIVER SWITCHING CHARACTERISTICS(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, thedevices are guaranteed not to enter shutdown. If the inputs are in this state for at least 300ns, the devices are guaranteed to have entered shutdown. See Low-Power Shutdown Mode section.MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers_______________________________________________________________________________________5Typical Operating Characteristics(V CC = +3.3V, T A = +25°C, unless otherwise noted.)252015105000.51.01.52.02.53.53.0OUTPUT CURRENT vs.RECEIVER OUTPUT LOW VOLTAGEM A X 3483E -01OUTPUT LOW VOLTAGE (V)O U T P U T C U R R E N T (m A )-20-18-16-14-12-10-8-6-4-2000.51.01.52.02.53.53.0OUTPUT CURRENT vs.RECEIVER OUTPUT HIGH VOLTAGEM A X 3483E -02OUTPUT HIGH VOLTAGE (V)O U T P U T C U R R E N T (m A )3.003.053.103.153.203.253.30-40-20020406010080RECEIVER OUTPUT HIGH VOLTAGEvs. TEMPERATURETEMPERATURE (°C)O U T P U T H I G H V O L T A G E (V )00.10.20.30.40.50.60.70.8-40-2020406010080RECEIVER OUTPUT LOW VOLTAGEvs. TEMPERATURETEMPERATURE (°C)O U T P U T L O W V O L T A G E (V )2505075100125150175024681012OUTPUT CURRENT vs.DRIVER OUTPUT LOW VOLTAGEM A X 3483E -07OUTPUT LOW VOLTAGE (V)O U T P U T C U R R E N T (m A )100908070605040302010000.5 1.0 1.5 2.0 2.5 3.53.0DRIVER OUTPUT CURRENT vs.DIFFERENTIAL OUTPUT VOLTAGEM A X 3483E -05DIFFERENTIAL OUTPUT VOLTAGE (V)O U T P U T C U R R E N T (m A )1.61.71.81.92.02.12.22.32.42.62.5-40-20020406010080DRIVER 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 )-100-80-60-40-20543210-7-6-3-4-5-2-1OUTPUT CURRENT vs.DRIVER OUTPUT HIGH VOLTAGEM A X 3483E -08OUTPUT HIGH VOLTAGE (V)O U T P U T C U R R E N T (m A )M A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers0.80.70.91.01.11.2-40-2020406010080SUPPLY CURRENT vs. TEMPERATURETEMPERATURE (°C)S U P P L Y C U R R E N T (m A )Typical Operating Characteristics (continued)(V CC = +3.3V, T A = +25°C, unless otherwise noted.)0102030405060708010090-40-2020406010080SHUTDOWN CURRENT vs. TEMPERATUREM A X 3483E -10TEMPERATURE (°C)S H U T D O W N C U R R E N T (n A )Pin DescriptionMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers_______________________________________________________________________________________7Figure 2. MAX3488E/MAX3490E Pin Configuration and Typical Operating CircuitFigure 3. MAX3491E Pin Configuration and Typical Operating CircuitFigure 1. MAX3483E/MAX3485E/MAX3486E Pin Configuration and Typical Operating CircuitM A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers8_______________________________________________________________________________________Figure 4. Driver V OD and V OC Figure 7. Driver Differential Output Delay and Transition TimesFigure 6. Receiver V OH and V OLFigure 5. Driver V OD with Varying Common-Mode VoltageMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers_______________________________________________________________________________________9Figure 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 )M A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers10______________________________________________________________________________________Figure 11. Receiver Propagation DelayFigure 12. Receiver Enable and Disable TimesNote 4: The input pulse is supplied by a generator with the following characteristics: f = 250kHz, 50% duty cycle, t r ≤6.0ns, Z O = 50Ω.Note 5: C L includes probe and stray capacitance._____________________Function TablesDevices with Receiver/Driver Enable(MAX3483E/MAX3485E/MAX3486E/MAX3491E)Table 1. Transmitting* B and A outputs are Z and Y, respectively, for full-duplex part (MAX3491E).X = Don’t care; High-Z = High impedanceTable 2. Receiving* DE is a “don’t care” (x) for the full-duplex part (MAX3491E).X = Don’t care; High-Z = High impedanceDevices without Receiver/Driver Enable(MAX3488E/MAX3490E)Table 3. TransmittingTable 4. Receiving___________Applications InformationThe MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E are low-power transceivers for RS-485 and RS-422 communications. The MAX3483E and MAX3488E can transmit and receive at data rates up to 250kbps, the MAX3486E at up to 2.5Mbps, and the MAX3485E/MAX3490E/MAX3491E at up to 12Mbps. The MAX3488E/MAX3490E/MAX3491E are full-duplex trans-ceivers, while the MAX3483E/MAX3485E/MAX3486E are half-duplex. Driver Enable (DE) and Receiver Enable (RE ) pins are included on the MAX3483E/MAX3485E/MAX3486E/MAX3491E. When disabled, the driver and receiver outputs are high impedance.Reduced EMI and Reflections (MAX3483E/MAX3486E/MAX3488E)The MAX3483E/MAX3488E are slew-rate limited, mini-mizing EMI and reducing reflections caused by improp-erly terminated cables. Figure 13 shows the driver output waveform of a MAX3485E/MAX3490E/MAX3491E transmitting a 125kHz signal, as well as the Fourier analysis of that waveform. High-frequency harmonics with large amplitudes are evident. Figure 14 shows the same information, but for the slew-rate-limited MAX3483E/MAX3488E transmitting the same signal. The high-frequency harmonics have much lower amplitudes,and the potential for EMI is significantly reduced.Low-Power Shutdown Mode(MAX3483E/MAX3485E/MAX3486E/MAX3491E)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 (high impedance). In shutdown, the devices typically draw only 2nA of supply current.For these devices, the t PSH and t PSL enable times assume the part was in the low-power shutdown mode;the t PZH and t PZL enable times assume the receiver or driver was disabled, but the part was not shut down.MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers______________________________________________________________________________________11INPUTS OUTPUT A, B RO ≥+0.2V 1≤-0.2V 0Inputs Open1INPUT OUTPUTS DI Z Y 101015MHz 500kHz/div 05MHz500kHz/div Figure 13. Driver Output Waveform and FFT Plot of MAX3485E/MAX3490E/MAX3491E Transmitting a 125kHz Signal Figure 14. Driver Output Waveform and FFT Plot of MAX3483E/ MAX3488E Transmitting a 125kHz SignalM A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers12______________________________________________________________________________________Figure 17. MAX3483E/MAX3488E Driver Propagation Delay Figure 19. MAX3483E/MAX3488E System Differential Voltage at 125kHz Driving 4000 Feet of Cable Figure 20. MAX3485E/MAX3490E/MAX3491E System Differential Voltage at 125kHz Driving 4000 Feet of CableDriver-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 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 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 Rate The 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 120Ωloads.For faster data rate transmission, please consult the fac-tory.±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 transmitter outputs and receiver inputs of this product family are characterized for protection to the following limits:1)±15kV using the Human Body Model2)±8kV using the Contact-Discharge method specifiedin 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 inter-est, which is then discharged into the test device through a 1.5kΩresistor.IEC 1000-4-2 The 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 current in IEC 1000-4-2, because series resistance is lower in the IEC 1000-4-2 model. Hence, the ESD with-stand 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 4 ESD contact-discharge test.Figure 21. Line Repeater for MAX3488E/MAX3490E/MAX3491EMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers ______________________________________________________________________________________13M A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491EThe 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 when I/O pins are contacted by handling equipment during test and assembly. Of course, all pins require this protection, not just RS-485 inputs and outputs.Typical ApplicationsThe MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E transceivers are designed for bidirectional data communications on multipoint bus transmission lines. Figures 24 and 25 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 21.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 possible. The slew-rate-limited MAX3483E/MAX3488E and the partially slew-rate-limited MAX3486E are more tolerant of imperfect termination.3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers14______________________________________________________________________________________Figure 22a. Human Body ESD Test ModelFigure 22b. Human Body Current WaveformFigure 23a. IEC 1000-4-2 ESD Test ModelFigure 23b. IEC 1000-4-2 ESD Generator Current WaveformMAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceivers______________________________________________________________________________________15Figure 25. MAX3488E/MAX3490E/MAX3491E Full-Duplex RS-485 NetworkFigure 24. MAX3483E/MAX3485E/MAX3486E Typical RS-485 NetworkM A X 3483E /M A X 3485E /M A X 3486E /M A X 3488E /M A X 3490E /M A X 3491E3.3V-Powered, ±15kV ESD-Protected, 12Mbps and Slew-Rate-Limited T rue RS-485/RS-422 T ransceiversTRANSISTOR COUNT: 761Chip InformationOrdering Information (continued)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©1999 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.。