MAX1474AXT-T中文资料
MAX471MAX472的中文资料大全
M A X471M A X472的中文资料大全(总4页)-本页仅作为预览文档封面，使用时请删除本页-MAX471/MAX472的特点、功能美国美信公司生产的精密高端电流检测放大器是一个系列化产品，有MAX471/MA X472、 MAX4172/MAX4173等。
它们均有一个电流输出端，可以用一个电阻来简单地实现以地为参考点的电流/电压的转换，并可工作在较宽电压内。
MAX471/MAX472具有如下特点：●具有完美的高端电流检测功能；●内含精密的内部检测电阻（MAX471）；●在工作温度范围内，其精度为2%；●具有双向检测指示，可监控充电和放电状态；●内部检测电阻和检测能力为3A，并联使用时还可扩大检测电流范围；●使用外部检测电阻可任意扩展检测电流范围（MAX472）；●最大电源电流为100μA；●关闭方式时的电流仅为5μA；●电压范围为3～36V；●采用8脚DIP/SO/STO三种封装形式。
MAX471/MAX472的引脚排列如图1所示，图2所示为其内部功能框图。
表1为MAX471/MAX472的引脚功能说明。
MAX471的电流增益比已预设为500μA/A，由于2kΩ的输出电阻（ROUT）可产生1V/A的转换，因此±3A时的满度值为3V.用不同的ROUT电阻可设置不同的满度电压。
但对于MAX471，其输出电压不应大于VRS+。
对于MAX472，则不能大于。
MAX471引脚图如图１所示，MAX472引脚图如图２所示。
MAX471/MAX472的引脚功能说明引脚名称功能MAX471MAX47211SHDN关闭端。
正常运用时连接到地。
当此端接高电平时，电源电流小于5μA2，3-RS+内部电流检测电阻电池（或电源端）。
“+”仅指示与SIGN输出有关的流动方向。
封装时已将2和3连在了一起-2空脚-3RG1增益电阻端。
通过增益设置电阻连接到电流检测电阻的电池端44GND地或电池负端55SIGN集电极开路逻辑输出端。
Maxxt中文使用说明书
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MEMORY存储芯片MAX1916EZT+T中文规格书
Detailed Description The MAX1916 provides constant-current bias supply for white LED designs. The MAX1916 uses a single resistor to set the bias current for up to three LEDs. LED bias currents are matched to 0.3% by the MAX1916’s unique current-matching architecture (Figure 1). Supply current (I EN) is a low 40µA in normal operation and 0.05µA when disabled.The MAX1916 offers several advantages over using ballast resistors, such as improved LED-to-LED bright-ness matching, lower bias variation with supply voltage changes, significantly lower dropout voltage, and in some applications, significantly improved efficiency.The MAX1916 achieves a 200mV dropout with a 9mAload on each output.For circuits requiring only one or two LEDs, leave unused LED outputs unconnected.Enable InputEN powers the input of the MAX1916. Drive EN high(> 2.5V) to enable the device; drive EN low (< 2.2V) to disable the device. When driven high, EN draws 40µAto power the IC. Driving EN low forces LED1, LED2,LED3, and SET into a high-impedance state.MAX1916Figure 1. MAX1916 Simplified Functional Diagram 找MEMORY、二三极管上美光存储M A X 1916Setting the Output Current SET controls the LED bias current. Current flowing into LED1, LED2, and LED3 is 230 times greater than the current flowing into SET. Set the output current as fol-lows:where V SET = 1.215V, V CTRL is an external voltage between 1.8V and 5.5V, and R SET is the resistor con-nected between V CTRL and SET (Figure 1).Applications Information 1)Very Low-Cost, High-Efficiency Solution (Figure 2).A battery (single Li+ or three NiMH cells) powers the LEDs directly. This is the least expensive and most efficient architecture. Due to the high forward voltage of white LEDs (3.3V), the LED brightness may dim slightly at the end of battery life. The MAX1916’s current-regulating architecture and low dropout greatly minimize this effect compared to using simple ballast resistors. The enable function of the MAX1916 turns on and off the LEDs. An exist-ing low-dropout regulator is used as V CTRL .2)Brightness Adjustment Using a DAC (Figure 3). A DAC is used as V CTRL such that the LED brightness may be dynamically adjusted to eliminate factory calibration. A battery (single Li+ or three NiMH cells) or a regulated power source drives the LEDs.3)Existing 5V Supply (Figure 4). Use an existing sys-tem regulator, such as the MAX684, to provide the required LED voltage and provide power to other circuits. Due to the high forward voltage of white LEDs (3.3V), use a 3.6V to 5.5V regulated supply to provide enough voltage headroom such that the LEDs will maintain constant brightness for any bat-tery voltage. Use the existing regulated supply as V CTRL .Chip Information TRANSISTOR COUNT: 220PROCESS: BiCMOS Low-Dropout, Constant-Current Triple White LED Bias SupplyFigure 2. Very Low-Cost, High-Efficiency SolutionFigure 3. Brightness Adjust Using DACFigure 4. Existing 5V Supply Circuit。
MAX1722EZK-T中文资料
MAX1722
FB 3
4
OUT
THIN SOT23-5
Pin Configurations are continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products
元器件交易网
19-1735; Rev 0; 7/01
1.5µA IQ, Step-Up DC-DC Converters in Thin SOT23-5
General Description
The MAX1722/MAX1723/MAX1724 compact, high-efficiency, step-up DC-DC converters are available in tiny, 5pin thin SOT23 packages. They feature an extremely low 1.5µA quiescent supply current to ensure the highest possible light-load efficiency. Optimized for operation from one to two alkaline or nickel-metal-hydride (NiMH) cells, or a single Li+ cell, these devices are ideal for applications where extremely low quiescent current and ultra-small size are critical. Built-in synchronous rectification significantly improves efficiency and reduces size and cost by eliminating the need for an external Schottky diode. All three devices feature a 0.5Ω N-channel power switch. The MAX1722/ MAX1724 also feature proprietary noise-reduction circuitry, which suppresses electromagnetic interference (EMI) caused by the inductor in many step-up applications. The family offers different combinations of fixed or adjustable outputs, shutdown, and EMI reduction (see Selector Guide). o o o o o o o o o o o
MAX1474中文资料
ELECTRICAL CHARACTERISTICS
(VDD = +5V, VSS = 0, TA = +25°C, unless otherwise noted.)
PARAMETER
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CONDCHARACTERISTICS Supply Voltage Supply Current
MAX1474 toc01
CS (pF)
CAPACITANCE vs. VOLTAGE (SINGLE ENDED)
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14.4
14.0
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1
2
3
4
5
VOLTAGE (V)
fDAT tDAT_HIGH
tSETUP tLOAD tRESET
25
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20
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20
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20
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20
ns
Note 1: Measurements made at CP with CM = GND.
2 _______________________________________________________________________________________
元器件交易网
19-1948; Rev 1; 3/01
Miniature Electronically Trimmable Capacitor
MAX1474
AAT
General Description
The MAX1474 is a fine-line (geometry) electronically trimmable capacitor (FLECAP) programmable through a simple digital interface. There are 32 programmable capacitance values ranging from 6.4pF to 13.3pF in 0.22pF increments (Table 1). The quartz dielectric capacitance is highly stable and exhibits a very low voltage coefficient. It has virtually no dielectric absorption and has a very low temperature drift coefficient (<33ppm/°C). The MAX1474 is programmed through two digital interface pins, which have Schmidt triggers and pulldown resistors to secure capacitance programming.
MEMORY存储芯片MAX478CSA-T中文规格书
MAX471/MAX472Precision, High-Side Current-Sense AmplifiersFigure 1. MAX471 Functional DiagramFigure 2. MAX472 Functional DiagramM A X 471/M A X 472for current summing. A single scaling resistor is required when summing OUT currents from multiple devices (Figure 3). Current can be integrated by con-necting OUT to a capacitive load.SIGN OutputThe current at OUT indicates magnitude. The SIGN out-put indicates the current’s direction. Operation of the SIGN comparator is straightforward. When Q1 (Figures 1 and 2) conducts, the output of A1 is high while A2’s output is zero. Under this condition, a high SIGN output indicates positive current flow (from RS+ to RS-). In bat-tery-operated systems, this is useful for determining whether the battery is charging or discharging. The SIGN output may not correctly indicate if the load cur-rent is such that I OUT is less than 3.5µA. The MAX471’s SIGN output accurately indicates the direction of cur-rent flow for load currents greater than 7mA.SIGN is an open-collector output (sinks current only),allowing easy interface with logic circuits powered from any voltage. Connect a 100k Ωpull-up resistor from SIGN to the logic supply. The convention chosen for the polarity of the SIGN output ensures that it draws no current when the battery is being discharged. If current direction is not needed, float the SIGN pin.Shutdown When SHDN is high, the MAX471/MAX472 are shut down and consume less than 18µA. In shutdown mode,SIGN is high impedance and OUT turns off.__________Applications Information MAX471The MAX471 obtains its power from the RS- pin. This includes MAX471 current consumption in the total sys-tem current measured by the MAX471. The small drop across R SENSE does not affect the MAX471’s perfor-mance.Resistor Selection Since OUT delivers a current, an external voltage gain-setting resistor (R OUT to ground) is required at the OUT pin in order to get a voltage. R SENSE is internal to the MAX471. RG1 and RG2 are factory trimmed for an out-put current ratio (output current to load current) of 500µA/A. Since they are manufactured of the same material and in very close proximity on the chip, they provide a high degree of temperature stability. Choose R OUT for the desired full-scale output voltage up to RS--1.5V (see the Current Output section).Precision, High-Side Current-Sense AmplifiersFigure 3. Paralleling MAX471s to Sense Higher Load Current Figure 4. MAX472 Standard Application Circuit。
1474A产品系列电缆技术数据表说明书
AWM Compliance:
AWM 2464
CEC / C(UL) Compliance: CMG
European Directive Compliance:
EU CE Mark, EU Directive 2015/863/EU (RoHS 2 amendment), EU Directive 2011/65/EU (RoHS 2), EU Directive 2012/19/EU (WEEE)
APAC Compliance:
China RoHS II (GB/T 26572-2011)
History
Update and Revision:
Revision Number: 0.394 Revision Date: 02-08-2022
Part Numbers
Variants
Item #
Color Putup Type Length
PVC - Polyvinyl Chloride 0.053 in (1.3 mm) 0.432 in (11.0 mm) Yes
Overall Cable Diameter (Nominal):
0ectrical Characteristics
Electricals
Inner Shield
Element
Shield Type
Material
Coverage Drainwire Type Notes
Pair(s)
Tape
Bi-Laminate (Alum+Poly) 100%
20 AWG (7x28) TC each pair
'Stranding@Conductor1' No Shield
MAX1487CSA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 .)。
ZST6000光伏逆变器综合测试仪入门手册V1.02
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ZST6000 入门手册
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安全信息
光伏逆变器综合测试仪安全符号如下所示。
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CAT Ⅱ(1000V)IEC 测量Ⅱ类，输入可连接到归属到Ⅱ类过电压条件下的电源 ( 最大 1000VAC)。 一般注意事项 针对人身安全与设备保护，列出注意事项如下所述： 保护功能有缺陷。在使用仪器之前，请对保护功能进行确认。如发现 保护接地或保险丝有缺陷，请勿继续使用本仪器； 请勿拆卸仪器的机箱。仪器内部有高压，非常危险。若要对仪器内部 进行检查和调试，请咨询广州致远电子股份有限公司； 出现异味或冒烟时。出现机体冒烟或散发异味等异常情况时，请直接 关闭电源，从插座拔掉电源插头，并切断连接在输入端子的测量回路 的电源。发生异常情况时，请咨询致远公司； 勿在易燃环境下操作仪器。请勿在含有易燃易爆液体或气体的环境里 使用本仪器； 请勿损坏电源线。请勿将物品摆放在电源线上，并使电源线远离热源。 将电源插头从插座拔出时，请勿拉扯电线，而应手持插头拔出。电源 线有破损时，请在确认好零件编号后再向经销商订购；
嵌入式短程无线通信工程系统硬件设计
嵌入式短程无线通信工程系统硬件设计摘要：在医疗、工业、智能建筑、消费电子等领域，短程无线通信工程设备设备应用日益广泛，并呈现强的增长势头。
本文较为详细地从元器件选择、原理图设计、PCB板设计、接口吸系统传输距离等方面介绍嵌入式短程无线通信工程系统硬件设计。
关键词：短程无线通信工程MAX1472 MAX1473 接口通信距离引言在短程无线通信工程系统中，常见的有基于802.11的无线局域网WLAN、蓝牙（blueTooth）、HomeRF及欧洲的HiperLAN(高性能无线局域网)。
但其硬件设计、接口方式、通信协议及软件堆栈复杂，需专门的开发系统，开发成本高、周期长，最终产品成本也高。
因此，这些技术在嵌入式系统中并未得到广泛应用相反，普通RF产品就不存在这些问题，加之短距离无线数据传输技术成熟，功能简单、携带方便，使得其在嵌入式短程无线产品中得到广泛应用，如医疗、工业、智能建筑、消费电子等领域。
这些产品一般均工作在无执照（Unlicensed）无线接入频段，如出一辙15/433/868/915MHz频段。
本文讨论的嵌入式短程无线通信系统，一般包括无线射频RF前端、微控制器（MCU）、I/O接口电路及其它外围设备等。
1元器件选择（1）微控制器的选择嵌入式系统选择处理器时主要需要考虑以下几个方面：处理器性能，所支持的开发工具，所支持的操作系统，过去的开发经验，处理器成本、功耗、代码兼容性及算法复杂性等。
（2）射频芯片的选择通常，射频芯片的功能框图如图形卡所示。
随着无线技术的发展，无线收发芯片的集成度、性能都大幅度提供，芯片性能也各有特色。
因而，无线收发芯片的选择在设计中是至关重要的。
正确的选择可以减小开发难度、缩短开发周期、降低成本、更快地将产品推向市场。
目前，生产此类芯片的厂家主要有Nordic、XEMICS、Chipcon、TI、Maxim等。
选择无线收发芯片时，应考虑以下几个因素：功耗、发射功率、接收灵敏度、传输速度、从待机模式到工作模式的唤醒时间、收发芯片所需的外围元件数量、芯片成本等；同时还须注意当地的无线电管理规定。
MEMORY存储芯片MAX490CSA+T中文规格书
±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 TransceiversFigure 6. IEC1000-4-2 ESD Test ModelFigure 8. Driver DC Test LoadFigure 7. IEC1000-4-2 ESD Generator Current WaveformFigure 9. Receiver Timing Test LoadFigure 4. Human Body ESD Test ModelFigure 5. Human Body Model Current Waveform MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E10±15kV ESD-Protected, Slew-Rate-Limited, Low-Power, RS-485/RS-422 TransceiversIt takes the drivers and receivers longer to become enabled from the low-power shutdown state (t ZH(SHDN), t ZL(SHDN)) than from the operating mode (t ZH, t ZL). (The parts are in operating mode if the RE, DE inputs equal a logical 0,1 or 1,1 or 0, 0.)Driver Output Protection Excessive output current and power dissipation caused by faults or by bus contention are prevented by two mechanisms. A foldback current limit on the output stage provides immediate protection against short circuits over the whole common-mode voltage range (see Typical Operating Characteristics). In addition, a thermal shut-down circuit forces the driver outputs into a high-imped-ance state if the die temperature rises excessively.Propagation Delay Many digital encoding schemes depend on the differ-ence between the driver and receiver propagation delay times. Typical propagation delays are shown in Figures 19–22 using Figure 18’s test circuit.The difference in receiver delay times, t PLH- t PHL, is typically under 13ns for the MAX481E, MAX485E, MAX490E, MAX491E, and MAX1487E, and is typically less than 100ns for the MAX483E and MAX487E–MAX489E.The driver skew times are typically 5ns (10ns max) for the MAX481E, MAX485E, MAX490E, MAX491E, and MAX1487E, and are typically 100ns (800ns max) for the MAX483E and MAX487E–MAX489E.Typical Applications The MAX481E, MAX483E, MAX485E, MAX487E–MAX491E, and MAX1487E transceivers are designed for bidirectional data communications on multipoint bus transmission lines. F igures 25 and 26 show typical net-work application circuits. These parts can also be used as line repeaters, with cable lengths longer than 4000 feet. To minimize reflections, the line should be terminated at both ends in its characteristic impedance, and stub lengths off the main line should be kept as short as possi-ble. The slew-rate-limited MAX483E and MAX487E–MAX489E are more tolerant of imperfect termination. Bypass the V CC pin with 0.1µF.Isolated RS-485 For isolated RS-485 applications, see the MAX253 and MAX1480 data sheets.Line Length vs. Data Rate The RS-485/RS-422 standard covers line lengths up to 4000 feet. Figures 23 and 24 show the system differen-tial voltage for the parts driving 4000 feet of 26AWG twisted-pair wire at 110kHz into 100Ωloads.Figure 18. Receiver Propagation Delay Test Circuit MAX481E/MAX483E/MAX485E/MAX487E–MAX491E/MAX1487E Maxim Integrated13。
MAX1978中文数据手册
用于Peltier模块的集成温度控制器概论MAX1978 / MAX1979是用于Peltier热电冷却器（TEC）模块的最小, 最安全, 最精确完整的单芯片温度控制器。
片上功率FET和热控制环路电路可最大限度地减少外部元件, 同时保持高效率。
可选择的500kHz / 1MHz开关频率和独特的纹波消除方案可优化元件尺寸和效率, 同时降低噪声。
内部MOSFET的开关速度经过优化, 可降低噪声和EMI。
超低漂移斩波放大器可保持±0.001°C的温度稳定性。
直接控制输出电流而不是电压, 以消除电流浪涌。
独立的加热和冷却电流和电压限制提供最高水平的TEC保护。
MAX1978采用单电源供电, 通过在两个同步降压调节器的输出之间偏置TEC, 提供双极性±3A输出。
真正的双极性操作控制温度, 在低负载电流下没有“死区”或其他非线性。
当设定点非常接近自然操作点时, 控制系统不会捕获, 其中仅需要少量的加热或冷却。
模拟控制信号精确设置TEC 电流。
MAX1979提供高达6A的单极性输出。
提供斩波稳定的仪表放大器和高精度积分放大器, 以创建比例积分（PI）或比例积分微分（PID）控制器。
仪表放大器可以连接外部NTC或PTC热敏电阻, 热电偶或半导体温度传感器。
提供模拟输出以监控TEC温度和电流。
此外, 单独的过热和欠温输出表明当TEC温度超出范围时。
片上电压基准为热敏电阻桥提供偏置。
MAX1978 / MAX1979采用薄型48引脚薄型QFN-EP 封装, 工作在-40°C至+ 85°C温度范围。
采用外露金属焊盘的耐热增强型QFN-EP封装可最大限度地降低工作结温。
评估套件可用于加速设计。
应用光纤激光模块典型工作电路出现在数据手册的最后。
WDM, DWDM激光二极管温度控制光纤网络设备EDFA光放大器电信光纤接口ATE特征♦尺寸最小, 最安全, 最精确完整的单芯片控制器♦片上功率MOSFET-无外部FET♦电路占用面积<0.93in2♦回路高度<3mm♦温度稳定性为0.001°C♦集成精密积分器和斩波稳定运算放大器♦精确, 独立的加热和冷却电流限制♦通过直接控制TEC电流消除浪涌♦可调节差分TEC电压限制♦低纹波和低噪声设计♦TEC电流监视器♦温度监控器♦过温和欠温警报♦双极性±3A输出电流（MAX1978）♦单极性+ 6A输出电流（MAX1979）订购信息* EP =裸焊盘。
MAX14878-MAX14880 高速传输接收器的中文名字说明书
General DescriptionThe MAX14878–MAX14880family of high-speed trans-ceivers improve communication and safety by integrating galvanic isolation between the CAN protocol controller side of the device and the physical wires of the network (CAN)bus.Isolation improves communication by breaking ground loops and reduces noise where there are large differences in ground potential between ports.The MAX14879provides up to2750V RMS(60s)of galvanic isolation,while the MAX14878/MAX14880provide up to 5000V RMS(60s)of galvanic isolation in8-pin and16-pin SOIC packages.All transceivers operate up to the maximum high-speed CAN data rate of1Mbps.The MAX14879/MAX14880fea-ture an integrated standby input(STB)on the isolated side of the transceiver to disable the driver and place the trans-ceiver in a low-power standby mode.The MAX14878does not include the standby input.The MAX14878–MAX14880transceivers feature integrat-ed protection for robust communication.The receiver input common-mode range is±25V,exceeding the ISO11898 specification of-2V to+7V,and are fault tolerant up to ±54V.Driver outputs/receiver inputs are also protected from±15kV electrostatic discharge(ESD)to GNDB on the bus side, as specified by the Human Body Model (HBM). Interfacing with CAN protocol controllers is simplified by the wide1.71V to5.5V supply voltage range(V DDA)on the controller side of the device.This supply voltage sets the interface logic levels between the transceiver and con-troller.The supply voltage range for the CAN bus side of the device is 4.5V to 5.5V (V DDB).The MAX14878–MAX14880are available in a wide-body 16-pin SOIC package with8mm of creepage and clear-ance.The MAX14878is also available in8-pin wide-body SOIC packages with5mm(MAX14878)and8mm (MAX14878W)creepage.All devices operate over the -40°C to +125°C temperature range.Applications●Industrial Controls●HVAC●Building Automation●Switching Gear Benefits and Features●Integrated Protection for Robust Communication• 2.75kV RMS, 3.5kV RMS, or 5kV RMS Withstand Isolation Voltage for 60s (Galvanic Isolation)•±25V Receiver Input Common-Mode Range•±54V Fault Protection on Receiver Inputs●High-Performance Transceiver Enables FlexibleDesigns•Wide 1.71V to 5.5V Supply for the CAN Controller Interface•Available 16-pin and 8-pin SOIC Package Pin Configurations•Data Rates up to 1Mbps (Max)•Dominant Timeout ProtectionSafety Regulatory Approvals●UL According to UL1577 (Basic Insulation) (16-PinPackage Devices Only)Ordering Information appears at end of data sheet.Click here to ask about the production status of specific part numbers.MAX14878–MAX14880 2.75kV, 3.5kV, and 5kV Isolated CANTransceiversSimplified Block DiagramAbsolute Maximum RatingsV DDA to GNDA.........................................................-0.3V to +6V V DDB to GNDB.........................................................-0.3V to +6V TXD to GNDA...........................................................-0.3V to +6V RXD to GNDA...........................................-0.3V to (V DDA+ 0.3V) STB to GNDB...........................................................-0.3V to +6V I.C. to GNDB.............................................-0.3V to (V DDB+ 0.3V) CANH or CANL to GNDB, (Continuous).................-54V to +54V Short-Circuit Duration (CANH to CANL).....................Continuous Short-Circuit Duration (RXD to GNDA or V DDA)........Continuous Continuous Power Dissipation (T A= +70ºC)16-pin W SOIC (derate 14.1mW/°C above +70°C)..1126.8mW 8-pin W SOICW8MS+1 (derate 9.39mW/°C above +70°C)........751.17mW W8MS+5 (derate 11.35mW/°C above +70°C)......908.06mW Operating Temperature Range.............................-40ºC to 125ºC Junction Temperature.......................................................+150ºC Storage Temperature Range..............................-60ºC to +150ºC Lead Temperature (soldering, 10s)...................................+300ºC Soldering Temperature (reflow)........................................+260ºCNOTE:See the Isolation section of the Electrical Characteristics table for maximum voltage from GNDA to GNDBStresses 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.Package InformationFor the latest package outline information and land patterns (footprints), go to /packages. 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.Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using afour-layer board. For detailed information on package thermal considerations, refer to / thermal-tutorial.Electrical Characteristics(V DDA=1.71V to5.5V,V DDB=4.5V to5.5V,T A=-40°C to+125°C,STB or I.C.=GNDB.Typical values are at T A=+25°C with GNDA = GNDB, V DDA= 3.3V, V DDB= 5V. (Notes 1, 2)PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS POWERProtocol Controller Side(A-Side) Voltage SupplyV DDA 1.71 5.5V CAN Bus Side (B-Side)Voltage SupplyV DDB 4.5 5.5VV DDA Supply Current I DDA V DDA= 5V0.340.83mA V DDA= 3.3V0.340.76V DDA= 1.8V0.330.64V DDB Supply Current I DDB V DDB= 5V, TXD = GNDA,R L= open4.37.3mA V DDB= 5V, TXD = GNDA, R L= 60Ω47.667.3V DDB= 5V, TXD = V DDA, R L= 60Ω 3.2V DDB= 5V, CANH shorted to CANL,TXD = V DDA3.2V DDB= 5V, CANH shorted to CANL,TXD = GNDA94140V DDB= 5V, TXD = V DDA, R L= 60Ω,STB = V DDB(MAX14879/MAX14880)0.40.8V DDA UndervoltageLockout Threshold,RisingV DDAUVLO_R 1.66VV DDA Undervoltage-Lockout Threshold,FallingV DDAUVLO_F 1.3 1.55VV DDB Undervoltage-Lockout Threshold,RisingV DDBUVLO_R 4.25VV DDB Undervoltage-Lockout Threshold,FallingV DDBUVLO_F 3.45V CANH, CANL TRANSMITTERDominant Output Voltage V O(DOM)V TXD= 0V,R L= 50Ω to 65ΩCANH 2.75 4.5VCANL0.5 2.25Electrical Characteristics (continued)(V DDA=1.71V to5.5V,V DDB=4.5V to5.5V,T A=-40°C to+125°C,STB or I.C.=GNDB.Typical values are at T A=+25°C with GNDA = GNDB, V DDA= 3.3V, V DDB= 5V. (Notes 1, 2)PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSDominant Differential Bus Output Voltage V OD(V CANH- V CANL),V TXD= 0V,R L= 50Ω to65Ω, Figure 1R CM is open 1.53V (V CANH- V CANL),V TXD= 0V,R L= 50Ω to65Ω, Figure 2R CM= 1.25kΩ,-17V < V CM<+17V1.53(V CANH- V CANL),V TXD= 0V,R L= 50Ω to65Ω, Figure 3RCM = 1.25kΩ,-25V < VCM <+25V1.13Recessive Voltage Output V ORV TXD= V DDA,No loadCANH23VCANL23Short-Circuit Current I SHORT V TXD= 0V CANH shorted toGNDB5075100mA CANL shorted toVDDB5075100Recessive Differential Bus Output Voltage V ODR(V CANH- V CANL),V TXD= V DDARL is open-500+50mVRL = 60Ω-120+12CANH/CANL OutputVoltage in Standby Mode V STBMAX14879/MAX14880 only,V TXD= V DDA, No load, STB = V DDB70175mVDC BUS RECEIVER (CANH and CANL externally driven)Common Mode Input Range V CMCANH or CANL toGNDB, RXDoutput validNormal operation-25+25VStandby mode(MAX14879/MAX14880 only)-12+12Differential Input Voltage V DIFF V TXD= V DDA Recessive0.5V Dominant, No load0.9Differential InputHysteresisV DIFF(HYST)125mVStandby Mode Differential Input Voltage MAX14879/MAX14880 only,V TXD= V DDA,V STB= V DDBRecessive0.45VDominant 1.15Common-Mode Input Resistance R INV TXD= V DDA, R IN= ΔV/∆I,∆V = +300mV, V STB= GNDB(MAX14879/MAX14880)1050kΩDifferential Input Resistance R IDV TXD= V DDA, R IN= ∆V/∆I,∆V = +300mV, V STB= GNDB(MAX14879/MAX14880)20100kΩInput Leakage Current I LKG V DDB= 0V, V CANH= V CANL= 5V310μA Input Capacitance C IN CANH or CANL to GNDB (Note 3)14.420pFElectrical Characteristics (continued)(V DDA=1.71V to5.5V,V DDB=4.5V to5.5V,T A=-40°C to+125°C,STB or I.C.=GNDB.Typical values are at T A=+25°C with GNDA = GNDB, V DDA= 3.3V, V DDB= 5V. (Notes 1, 2)PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Differential InputCapacitanceC IND CANH to CANL (Note 3)7.210pF LOGIC INTERFACE (RXD, TXD, STB)Input High Voltage V IH TXD 1.71V ≤ V DDA<2.25V0.75 xV DDAV 2.25V ≤ V DDA≤5.5V0.7 xV DDASTB (MAX14879/MAX14880 only)0.7 xV DDBInput Low Voltage V IL TXD, 1.71 ≤ V DDA< 2.25V0.7V TXD, 2.25V ≤ V DDA≤ 5.5V0.8STB (MAX14879/MAX14880 only)0.8Output High Voltage V OH RXD, I SOURCE= 4mA V DDA-0.4VOutput Low Voltage V OL RXD, I SINK= 4mA0.4V Input Pullup Current I PU TXD-10-5-1.5μA Input PulldownResistanceR PD STB (MAX14879/MAX14880 only)75250kΩInput Capacitance5pF PROTECTIONFault Protection Range CANH to GNDB, CANL to GNDB-54+54VESD Protection (CANH and CANL to GNDB)IEC 61000-4-2 Air-Gap Discharge±10kV IEC 61000-4-2 Contact Discharge±5Human Body Model±15ESD Protection (CANH and CANL to GNDA)IEC 61000-4-2 Contact Discharge±3kV IEC 61000-4-2 Air Gap Discharge, 330pFcapacitor connected between GNDA andGNDB±10ESD Protection (AllOther Pins)Human body model±2kV Thermal ShutdownThresholdTemperature rising+160°C Thermal ShutdownHysteresis13°CElectrical Characteristics - Switching(V DDA=1.71V to5.5V,V DDB=4.5V to5.5V,T A=-40°C to+125°C,STB or I.C.=GNDB.Typical values are at T A=+25°C with GNDA = GNDB, V DDA= 3.3V, V DDB= 5V, STB = GNDB.)PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSDifferential Driver Output Rise Time t RR L= 60Ω, C L= 100pF, R CM isopen, Figure 120nsElectrical Characteristics - Switching (continued)(V DDA=1.71V to5.5V,V DDB=4.5V to5.5V,T A=-40°C to+125°C,STB or I.C.=GNDB.Typical values are at T A=+25°C with GNDA = GNDB, V DDA= 3.3V, V DDB= 5V, STB = GNDB.)PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSDifferential Driver Output Fall Time t FR L= 60Ω, C L= 100pF, R CM isopen, Figure 133nsTXD to RXD Loop Delay t LOOP R L= 60Ω, C L= 100pF,C RXD= 15pF, Dominant to recessive andrecessive to dominant. Figure 2210nsTXD Propagation Delay t PDTXD_RDR L= 60Ω,C L= 100pF,R CM open,Figure 1Recessive toDominant95ns t PDTXD_DRR L= 60Ω,C L= 100pF,R CM open,Figure 2Dominant toRecessive95RXD Propagation Delay t PDRXD_RDC L= 15pF,Figure 3Recessive toDominant115ns t PDRXD_DRC L= 15pF,Figure 4Dominant toRecessive115TXD Dominant Timeout t DOM(Note 4) 1.4 4.8msUndervoltage Detection Time to Normal Operation t UV(VDDA),t UV(VDDB)110230μsWake-up Time to Dominant State t WAKEMAX14879/MAX14880 only, Instandby mode (V STB= V DDB), Figure 40.55μsStandby Propagation Delay MAX14879/MAX14880 only, RXD,Dominant to recessive, V STB= V DDB,C L= 15pF285500nsStandby to NormalMode Delayt EN MAX14879/MAX14880 only40μsNormal to Standby Dominant Mode Delay MAX14879/MAX14880 only,(V CANH- V CANL) > 1.2V65μsElectrical Characteristics–Package Insulation and Safety Related Specifications: W 16-SOIC(V DDA=1.71V to5.5V,V DDB=4.5V to5.5V,T A=-40°C to+125°C,STB or I.C.=GNDB.Typical values are at T A=+25°C with GNDA = GNDB, V DDA= 3.3V, V DDB= 5V, STB = GNDB.) (Note 5)PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Insulation Resistance RIO T A= 25°C, V IO= 500V>1012ΩBarrier Capacitance C IO GNDA to GNDB2pF Minimum CreepageDistanceCPG8mm Minimum ClearanceDistanceCLR8mm Internal Clearance Distance through insulation0.015mmElectrical Characteristics–Package Insulation and Safety Related Specifications: W 16-SOIC (continued)(V DDA=1.71V to5.5V,V DDB=4.5V to5.5V,T A=-40°C to+125°C,STB or I.C.=GNDB.Typical values are at T A=+25°C with GNDA = GNDB, V DDA= 3.3V, V DDB= 5V, STB = GNDB.) (Note 5)PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Comparative TrackingIndexCTI550Electrical Characteristics–Package Insulation and Safety Related Specifications: W 8-SOIC(V DDA-V GNDA=1.71V to5.5V,V DDB-V GNDB=1.71V to5.5V,C L=15pF,T A=-40°C to+125°C,unless otherwise noted.Typical values are at V DDA- V GNDA= 3.3V, V DDB- V GNDB= 3.3V, GNDA = GNDB, T A= 25°C, unless otherwise noted.) (Notes 2,3) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Insulation Resistance RIO T A= 25°C, V IO= 500V> 1012ΩBarrier Capacitance C IO GNDA to GNDB2pFMinimum Creepage Distance CPGMAX14878 5.5mm MAX14878W8Minimum Clearance Distance CLRMAX14878 5.5mm MAX14878W8Internal Clearance Distance through insulation0.015mm Comparative TrackingIndexCTI>400Electrical Characteristics–Insulation Characteristics (As Defined by VDE 0884-10): W 16-SOIC(V DDA=1.71V to5.5V,V DDB=4.5V to5.5V,T A=-40°C to+125°C,STB or I.C.=GNDB.Typical values are at T A=+25°C with GNDA = GNDB, V DDA= 3.3V, V DDB= 5V, STB = GNDB.) (Note 5)PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSPartial Discharge V PR Method B1 =V IORM x 1.875(t = 1s, partialdischarge < 5pC)MAX148791182V PMAX14878/MAX148802250Maximum Repetitive Peak Voltage V IORMMAX14879630V P MAX14878/MAX148801200Maximum Working Voltage V IOWMGNDA to GNDBcontinuousMAX14879445V RMSMAX14878/MAX14880848Maximum Transient Overvoltage V IOTMMAX148794600V P MAX14878/MAX148808400Isolation Voltage V ISO GNDA to GNDB for60sMAX14879 2.75kV RMSMAX14878/MAX148805Electrical Characteristics–Insulation Characteristics (As Defined by VDE 0884-10): W 16-SOIC (continued)(V DDA=1.71V to5.5V,V DDB=4.5V to5.5V,T A=-40°C to+125°C,STB or I.C.=GNDB.Typical values are at T A=+25°C with GNDA = GNDB, V DDA= 3.3V, V DDB= 5V, STB = GNDB.) (Note 5)PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Maximum SurgeIsolation VoltageV IOSM IEC 61000-4-5, Basic insulation10kV Barrier Resistance R S T A= +150°C, V IO= 500V>109ΩClimate Category 40/125/21Pollution Degree DIN VDE 0110, Table 12Electrical Characteristics–Insulation Characteristics: W 8-SOIC(V DDA=1.71V to5.5V,V DDB=4.5V to5.5V,T A=-40°C to+125°C,STB or I.C.=GNDB.Typical values are at T A=+25°C with GNDA = GNDB, V DDA= 3.3V, V DDB= 5V, STB = GNDB.) (Note 5)PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITSMaximum Repetitive Peak Voltage V IORMMAX14878630V P MAX14878W1200Maximum Working Voltage V IOWMGNDA to GNDBcontinuousMAX14878445V RMSMAX14878W848Maximum Transient Overvoltage V IOTMMAX148785000V P MAX14878W8400Isolation Voltage V ISO GNDA to GNDB for60sMAX14878 3.5kV RMSMAX14878W5Maximum SurgeIsolation VoltageV IOSM IEC 61000-4-5, Basic insulation10kV Barrier Resistance R S T A= +150°C, V IO= 500V>109ΩClimate Category 40/125/21Pollution Degree2Note 1:All devices 100% production tested at T A= +25°C. Specifications over temperature are guaranteed by design.Note 2:All currents into the device are positive.All currents out of the device are negative.All voltages referenced to their respective ground (GNDA or GNDB), unless otherwise noted.Note 3:Not production tested. Guaranteed at T A= +25°C.Note 4:The dominant timeout feature releases the bus when TX is held low longer than t DO.CAN protocol guarantees a maximum of11successive dominant bits in any transmission.The minimum data rate allowed by the dominant timeout,then,is11/ t DO(min).Note 5:All16-pin package devices are100%production tested for high voltage conditions(this does not apply to the8-pin MAX14878AWA).Typical Operating Characteristics(V DDA= 3.3V, V DDB= 5V, 60Ω load between CANH and CANL, T A= +25°C, unless otherwise noted.)Typical Operating Characteristics (continued)(V DDA= 3.3V, V DDB= 5V, 60Ω load between CANH and CANL, T A= +25°C, unless otherwise noted.)Pin DescriptionPINNAME FUNCTIONREFSUPPLYTYPEMAX14878 16-PIN MAX148788-PINMAX14879,MAX14880CONTROLLER SIDE (A-SIDE)131V DDA Power Supply Input for theController Side/A-Side. BypassV DDA to GNDA with 0.1μFcapacitor as close to the deviceas possible.V DDA Power2, 842, 8GNDA Controller Side/A-Side Ground V DDA Ground315RXD Receiver Output. RXD is highwhen the bus is in the recessivestate. RXD is low when the bus isin the dominant state.V DDA Digital Output4, 5, 7-4, 6, 7N.C.No Connection. Not internally connected. Connect to GNDA, V DDA, or leave unconnected.623TXD Transmit Data Input. CANH andCANL are in the dominant statewhen TXD is low. CANH andCANL are in the recessive statewhen TXD is high.V DDA Digital InputCAN BUS SIDE (B-SIDE)9, 1559, 15GNDB CAN Bus Side/B-Side Ground V DDB Ground10, 14-10I.C.Internally Connected. Connect to GNDB or leave unconnected.11-11I.C Internally Connected. Connect to GNDB, V DDB, or leave unconnected.12612CANL Low-Level CAN Differential BusLineV DDBDifferentialI/O13713CANH High-Level CAN Differential BusLineV DDBDifferentialI/OPin Description (continued)PINNAME FUNCTIONREFSUPPLYTYPEMAX14878 16-PIN MAX148788-PINMAX14879,MAX14880--14STB Standby Input, Active High. DriveSTB high to disable the CAN busdriver and place the transceiverin low-power standby mode.Drive STB low for normaloperation.V DDB Digital Input16816V DDB Power Supply Input for the CANBus Side/B-Side. Bypass V DDBto GNDB with a 0.1μF capacitoras close to the device aspossible.V DDB PowerDetailed DescriptionThe MAX14878–MAX14880isolated controller area network(CAN)transceivers provide2750V RMS or5000V RMS(60s) of galvanic isolation between the cable side(B-side)of the transceiver and the controller side(A-side).These devices allow up to1Mbps communication across an isolation barrier when a large potential exists between grounds on each side of the barrier.CANH and CANL outputs are short-circuit current limited and are protected against excessive power dissipation by thermal shutdown circuitry that places the driver outputs in a high-impedance state.IsolationData isolation is achieved using integrated capacitive isolation that allows data transmission between the controller side and cable side of the transceiver.Fault ProtectionThe MAX14878–MAX14880feature±54V fault protection on the CANH and CANL bus lines.When CANH or CANL is pulled above+30V(typ)or below-30V(typ),the I/O is set to high impedance.This wide fault protection range simplifies selecting external TVS components for surge protection.TransmitterThe transmitter converts a single-ended input signal(TXD)from the CAN controller to differential outputs for the bus lines (CANH, CANL). The truth table for the transmitter and receiver is given in Table 1.Transmitter Dominant TimeoutThe MAX14878–MAX14880feature a transmitter-dominant timeout(t DOM)that prevents erroneous CAN controllers from clamping the bus to a dominant level by maintaining a continuous low TXD signal.When TXD remains in the dominant state (low) for greater than t DOM, the transmitter is disabled, releasing the bus to a recessive state (Table 1).After a dominant timeout fault, normal transmitter function is re-enabled on the rising edge of a TXD.The transmitter-dominant timeout limits the minimum possible data rate to 9kbps for standard CAN protocol.Driver Output ProtectionThe MAX14878–MAX14880feature integrated circuitry to protect the transmitter output stage against a short-circuit to a positive or negative voltage by limiting the driver current.The transmitter returns to normal operation once the short is removed.Thermal shutdown further protects the transceiver from excessive temperatures that may result from a short by setting the transmitter outputs to high impedance when the junction temperature exceeds+160°C(typ).The transmitter returns to normal operation when the junction temperature falls below the thermal shutdown hysteresis.ReceiverThe receiver reads the differential input from the bus(CANH,CANL)and transfers this data as a single-ended output (RXD)to the CAN controller.During normal operation,a comparator senses the difference between CANH and CANL, V DIFF=(V CANH-V CANL),with respect to an internal threshold of0.7V(typ).If V DIFF>0.9V,a logic-low is present on RXD. If V DIFF< 0.5V, a logic-high is present.The CANH and CANL common-mode range is±25V.RXD is logic-high when CANH and CANL are shorted or terminated and undriven.Thermal ShutdownIf the junction temperature exceeds+160°C(typ),the device is switched off.During thermal shutdown,CANH and CANL are high-impedance and all IC functions are disabled.The transmitter outputs are re-enabled and the device resumes normal operation when the junction temperature drops below 147°C (typ).Table 1. Transmitter and Receiver Truth Table When Not Connected to the Bus TXD TXD LOW TIME CANH CANL BUS STATE RXD LOW< t DOM HIGH LOW DOMINANT LOW LOW> t DOM V DDB/2V DDB/2RECESSIVE HIGH HIGH X V DDB/2V DDB/2RECESSIVE HIGHApplications InformationReduced EMI and ReflectionsIn multidrop CAN applications,it is important to maintain a single linear bus of uniform impedance that is properly terminated at each end. A star configuration should never be used.Any deviation from the end-to-end wiring scheme creates a stub.High-speed data edges on a stub can create reflections back down the bus.These reflections can cause data errors by eroding the noise margin of the system.Although stubs are unavoidable in a multidrop system,care should be taken to keep these stubs as short as possible,especially when operating with high data rates.Typical Operating CircuitOrdering InformationPART NUMBER ISOLATION VOLTAGE (kV RMS)STANDBY OPERATING TEMPERATURE PACKAGE MAX14878AWA+ 3.5NO-40°C to +125°C W 8-SOIC MAX14878AWA+T 3.5NO-40°C to +125°C W 8-SOIC MAX14878AWE+5NO-40°C to +125°C W 16-SOIC MAX14878AWE+T5NO-40°C to +125°C W 16-SOIC MAX14878WAWA+5NO-40°C to +125°C W 8-SOIC MAX14878WAWA+T5NO-40°C to +125°C W 8-SOIC MAX14879AWE+ 2.75YES-40°C to +125°C W 16-SOIC MAX14879AWE+T 2.75YES-40°C to +125°C W 16-SOIC MAX14880AWE+5YES-40°C to +125°C W 16-SOIC MAX14880AWE+T5YES-40°C to +125°C W 16-SOICRevision HistoryREVISION NUMBER REVISIONDATEDESCRIPTIONPAGESCHANGED06/17Initial release—18/17Updated parameters in Electrical Characteristics table and added Typical Operating Circuit7, 14 210/17Corrected the Pin Description section for internally connected pins; updated Figure 29, 12 33/18Updated the Safety Regulatory Approvals section1 46/18Updated Pin Description table1253/19Updated the General Description, Benefits and Features, Package Information, Electrical Characteristics, Pin Configuration, and Pin Description to add a Wide 8-Pin SOIC package;added MAX14878AWA+ and MAX14878AWA+T to the Ordering Information table1, 3, 8,12, 1465/19Updated the General Description, Benefits and Features, Safety Regulatory Approvals,Electrical Characteristics–Package Insulation and Safety Related Specifications: W 8-SOIC, Electrical Characteristics–Insulation Characteristics (As Defined by VDE 0884-10): W16-SOIC, Electrical Characteristics–Insulation Characteristics: W 8-SOIC, and OrderingInformation sections1–16709/20Updated the General Description, Absolute Maximum Ratings, Package Information,Electrical Characteristics–Package Insulation and Safety Related Specifications: W 8-SOIC,Electrical Characteristics–Insulation Characteristics: W 8-SOIC, and Ordering Informationsections1, 3, 8-9,19For pricing, delivery, and ordering information, please visit Maxim Integrated’s online storefront at https:///en/storefront/storefront.html. Maxim 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.。
MAX479CSD+T中文资料
___________________________Features
o 17µA Max Supply Current (MAX478A/MAX479A) o 70µV Max Offset Voltage (MAX478A) o Single-Supply Operation: Input Voltage Range Includes Ground Output Swings to Ground While Sinking Current No Pull-Down Resistors Required o Dual Op Amp in 8-Pin DIP/SO Package (MAX478) Quad Op Amp in 14-Pin DIP/SO Package (MAX479) o 250pA Max Input Offset Current (MAX478A/MAX479A) o 0.5µV/°C Offset-Voltage Drift o Output Sources and Sinks 5mA Load Current
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.
MAX4351EKA+T中文资料
General DescriptionThe MAX4350 single and MAX4351 dual op amps are unity-gain-stable devices that combine high-speed per-formance with rail-to-rail outputs. Both devices operate from dual ±5V supplies. The common-mode input volt-age range extends to the negative power-supply rail. The MAX4350/MAX4351 require only 6.9mA of quies-cent supply current per op amp while achieving a 210MHz -3dB bandwidth and a 485V/µs slew rate. Both devices are excellent solutions in low-power systems that require wide bandwidth, such as video, communi-cations, and instrumentation.The MAX4350 is available in an ultra-small 5-pin SC70package and the MAX4351 is available in a space-saving 8-pin SOT23 package.ApplicationsSet-Top BoxesSurveillance Video Systems Video Line DriversAnalog-to-Digital Converter Interface CCD Imaging SystemsVideo Routing and Switching Systems Digital CamerasFeatures♦Ultra-Small 5-Pin SC70, 5-Pin SOT23, and 8-Pin SOT23 Packages ♦Low Cost♦High Speed210MHz -3dB Bandwidth 55MHz 0.1dB Gain Flatness 485V/µs Slew Rate ♦Rail-to-Rail Outputs♦Input Common-Mode Range Extends to V EE ♦Low Differential Gain/Phase: 0.02%/0.08°♦Low Distortion at 5MHz-65dBc SFDR-63dB Total Harmonic DistortionMAX4350/MAX4351Ultra-Small, Low-Cost, 210MHz, Dual-SupplyOp Amps with Rail-to-Rail Outputs________________________________________________________________Maxim Integrated Products 1Pin ConfigurationsTypical Operating Circuit19-1989; Rev 1; 10/05For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .M A X 4350/M A X 4351Ultra-Small, Low-Cost, 210MHz, Dual-Supply Op Amps with Rail-to-Rail Outputs 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSDC ELECTRICAL CHARACTERISTICS(V CC = +5V, V EE = -5V, R L = ∞to 0V, V OUT = 0, T A = T MIN to T MAX , unless otherwise noted. Typical values are at T A = +25°C.) (NoteSupply Voltage (V CC to V EE )................................................+12V IN_-, IN_+, OUT_..............................(V EE - 0.3V) to (V CC + 0.3V)Output Short-Circuit Current to V CC or V EE ......................150mA Continuous Power Dissipation (T A = +70°C)5-Pin SC70 (derate 2.5mW/°C above +70°C).............200mW 5-Pin SOT23 (derate 7.1mW/°C above +70°C)...........571mW8-Pin SOT23 (derate 5.26mW/°C above +70°C).........421mW 8-Pin SO (derate 5.9mW/°C above +70°C).................471mW Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10s).................................+300°CStresses 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 at 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.MAX4350/MAX4351Ultra-Small, Low-Cost, 210MHz, Dual-SupplyOp Amps with Rail-to-Rail Outputs_______________________________________________________________________________________3AC ELECTRICAL CHARACTERISTICSM A X 4350/M A X 4351Ultra-Small, Low-Cost, 210MHz, Dual-Supply Op Amps with Rail-to-Rail Outputs 4_______________________________________________________________________________________Typical Operating Characteristics(V CC = +5V, V EE = -5V, V CM = 0V, A VCL = +1V/V, R F = 24Ω, R L = 100Ωto 0, T A = +25°C, unless otherwise noted.)4-6100k10M 100M1M1GSMALL-SIGNAL GAIN vs. FREQUENCYFREQUENCY (Hz)G A I N (d B )-5-4-3-2-101234-6100k 10M 100M 1M 1G LARGE-SIGNAL GAIN vs. FREQUENCYFREQUENCY (Hz)G A I N (d B )-5-4-3-2-101230.4-0.6100k 10M 100M 1M 1GGAIN FLATNESS vs. FREQUENCYFREQUENCY (Hz)G A I N (d B )-0.5-0.4-0.3-0.2-0.100.10.20.3100k10M 1M100M1GOUTPUT IMPEDANCE vs. FREQUENCYM A X 4350-05FREQUENCY (Hz)I M P E D A N C E (Ω)1000.010.1110-10-100100k100M10M1MDISTORTION vs. FREQUENCY-70-90-30-500-60-80-20-40FREQUENCY (Hz)D I S T O R T I O N (d B c )-10-100100k100M10M1MDISTORTION vs. FREQUENCY-70-90-30-500-60-80-20-40FREQUENCY (Hz)D I S T O R T I O N (d B c )-10-100100k100M10M1MDISTORTION vs. FREQUENCY-70-90-30-500-60-80-20-40FREQUENCY (Hz)D I S T O R T I O N (d B c )-100-70-80-90-60-50-40-30-20-100040020060080010001200DISTORTION vs. LOAD RESISTANCER LOAD (Ω)D I S T O R T I O N (d B c )0.4-0.6100k1M10M 100M1GGAIN FLATNESS vs. FREQUENCY-0.4FREQUENCY (Hz)G A I N (d B )-0.200.20.1-0.1-0.3-0.50.3MAX4350/MAX4351Ultra-Small, Low-Cost, 210MHz, Dual-SupplyOp Amps with Rail-to-Rail Outputs_______________________________________________________________________________________51000100DIFFERENTIAL GAIN AND PHASE-0.01000.0050.0150.025IRED I F F P H A SE (d e g r e e s )D I F F G A I N (%)M A X 4350-11IRE-0.0050.0200.010-0.040.020.040.080.1200.100.06-0.020-100100k 10M 100M 1M 1GCOMMON-MODE REJECTIONvs. FREQUENCYM A X 4350-12FREQUENCY (Hz)C M R (d B )-90-80-70-60-50-40-30-20-10P S R (d B )0-100100k10M 100M1M1GPOWER-SUPPLY REJECTIONvs. FREQUENCYM A X 4350-13FREQUENCY (Hz)-90-80-70-60-50-40-30-20-1000.40.21.00.80.61.41.21.60300400100200500600700800900OUTPUT VOLTAGE SWING vs. LOAD RESISTANCER LOAD (Ω)V S W I N G (V )INPUT 50mV/divOUTPUT 50mV/divSMALL-SIGNAL PULSE RESPONSE20ns/divR F = 24ΩA VCL = +1V/VINPUT 25mV/divOUTPUT 50mV/divSMALL-SIGNAL PULSE RESPONSE20ns/div R F = 500ΩA VCL = +2V/V INPUT 10mV/divOUTPUT 50mV/divSMALL-SIGNAL PULSE RESPONSE20ns/div R F = 500ΩA VCL = +5V/VINPUT 1V/divOUTPUT 1V/divLARGE-SIGNAL PULSE RESPONSE20ns/divR F = 24ΩA VCL = +1V/V-100-70-80-90-60-50-40-30-20-1000.51.01.52.0DISTORTION vs. VOLTAGE SWINGVOLTAGE SWING (Vp-p)D I S T O R T I O N (d B c )Typical Operating Characteristics (continued)(V CC = +5V, V EE = -5V, V CM = 0V, A VCL = +1V/V, R F = 24Ω, R L = 100Ωto 0, T A = +25°C, unless otherwise noted.)M A X 4350/M A X 4351Ultra-Small, Low-Cost, 210MHz, Dual-Supply Op Amps with Rail-to-Rail Outputs 6_______________________________________________________________________________________Typical Operating Characteristics (continued)(V CC = +5V, V EE = -5V, V CM = 0V, A VCL = +1V/V, R F = 24Ω, R L = 100Ωto 0, T A = +25°C, unless otherwise noted.)20ns/divINPUT 1V/divINPUT 1V/divLARGE-SIGNAL PULSE RESPONSER F = 500ΩA VCL = +2V/VV O L T A G E N O I S E (n V /H z )110k100101k100k1M10MVOLTAGE NOISE vs. FREQUENCYFREQUENCY (Hz)11010091110131********20010030040050250150350450500ISOLATION RESISTANCE vs. CAPACITIVE LOADC LOAD (pF)R I S O (Ω)0501001502002503000200100300400500600700800SMALL-SIGNAL BANDWIDTH vs. LOAD RESISTANCEM A X 4350-24R LOAD (Ω)B A N D W I D T H (M H z )8001001k 10kOPEN-LOOP GAIN vs. LOAD RESISTANCE2010M A X 4350-25R LOAD (Ω)O P E N -L O O P G A I N (d B c )4030506070C U R R E N T N O I S E (p A /H z)110k100101k100k1M10MCURRENT NOISE vs. FREQUENCYFREQUENCY (Hz)110100MAX4351CROSSTALK vs. FREQUENCYM A X 4350-26FREQUENCY (Hz)C R O S S T A L K (d B )-140-80-100-120-60-40-2002040600.1M1M10M 100M1GINPUT 500mV/divOUTPUT 1V/divLARGE-SIGNAL PULSE RESPONSE20ns/divR F = 500ΩA VCL = +2V/VDetailed DescriptionThe MAX4350/MAX4351 are single-supply, rail-to-rail,voltage-feedback amplifiers that employ current-feed-back techniques to achieve 485V/µs slew rates and 210MHz bandwidths. Excellent harmonic distortion and differential gain/phase performance make these ampli-fiers an ideal choice for a wide variety of video and RF signal-processing applications.The output voltage swings to within 125mV of each sup-ply rail. Local feedback around the output stage ensures low open-loop output impedance to reduce gain sensitivity to load variations. The input stage per-mits common-mode voltages beyond the negative sup-ply and to within 2.25V of the positive supply rail.Applications InformationChoosing Resistor ValuesUnity-Gain ConfigurationThe MAX4350/MAX4351 are internally compensated for unity gain. When configured for unity gain, a 24Ωresis-tor (R F ) in series with the feedback path optimizes AC performance. This resistor improves AC response by reducing the Q of the parallel LC circuit formed by the parasitic feedback capacitance and inductance.Inverting and Noninverting ConfigurationsSelect the gain-setting feedback (R F ) and input (R G )resistor values to fit your application (Figures 1a and 1b). Large resistor values increase voltage noise and interact with the amplifier’s input and PC board capaci-tance. This can generate undesirable poles and zeros and decrease bandwidth or cause oscillations. For example, a noninverting gain-of-two configuration (R F =R G ) using 1k Ω resistors, combined with 1pF of amplifier input capacitance and 1pF of PC board capacitance,causes a pole at 159MHz. Since this pole is within the amplifier bandwidth, it jeopardizes stability. Reducing the 1k Ωresistors to 100Ωextends the pole frequency to 1.59GHz, but could limit output swing by adding 200Ωin parallel with the amplifier’s load resistor.Layout and Power-Supply BypassingThese amplifiers operate from dual ±5V supplies. Bypass each supply with a 0.1µF capacitor to ground.Maxim recommends using microstrip and stripline tech-niques to obtain full bandwidth. To ensure that the PC board does not degrade the amplifier’s performance,design it for a frequency greater than 1GHz. Pay care-MAX4350/MAX4351Ultra-Small, Low-Cost, 210MHz, Dual-SupplyOp Amps with Rail-to-Rail Outputs_______________________________________________________________________________________7Figure 1a. Noninverting Gain ConfigurationFigure 1b. Inverting Gain Configurationful attention to inputs and outputs to avoid large para-sitic capacitance. Whether or not you use a constant-impedance board, observe the following design guide-lines:•Don’t use wire-wrap boards; they are too inductive.•Don’t use IC sockets; they increase parasitic capaci-tance and inductance.•Use surface-mount instead of through-hole compo-nents for better high-frequency performance.•Use a PC board with at least two layers; it should be as free from voids as possible.•Keep signal lines as short and as straight as possi-ble. Do not make 90°turns; round all corners.Rail-to-Rail Outputs, Ground-Sensing InputThe input common-mode range extends from V EE to (V CC - 2.25V) with excellent common-mode rejection. Beyond this range, the amplifier output is a nonlinear function of the input, but does not undergo phase reversal or latchup. The output swings to within 125mV of either power-supply rail with a 2k Ωload.Output Capacitive Load and StabilityThe MAX4350/MAX4351 are optimized for AC perfor-mance. They are not designed to drive highly reactive loads, which decrease phase margin and may produce excessive ringing and oscillation. Figure 2 shows a cir-cuit that eliminates this problem. Figure 3 is a graph of the I solation Resistance (R ISO ) vs. Capacitive Load.Figure 4 shows how a capacitive load causes exces-sive peaking of the amplifier’s frequency response if the capacitor is not isolated from the amplifier by a resistor. A small isolation resistor (usually 20Ωto 30Ω)placed before the reactive load prevents ringing and oscillation. At higher capacitive loads, AC performance is controlled by the interaction of the load capacitance and the isolation resistor. Figure 5 shows the effect of a 27Ωisolation resistor on closed-loop response.Coaxial cable and other transmission lines are easily driven when properly terminated at both ends with their characteristic impedance. Driving back-terminated transmission lines essentially eliminates the line’s capacitance.M A X 4350/M A X 4351Ultra-Small, Low-Cost, 210MHz, Dual-Supply Op Amps with Rail-to-Rail Outputs 8_______________________________________________________________________________________Figure 2. Driving a Capacitive Load Through an Isolation Resistor 302520510150CAPACITIVE LOAD (pF)50100200150250I S O L A T I O N R E S I S T A N C E (Ω)Figure 3. Isolation Resistance vs. Capacitive LoadMAX4350/MAX4351Ultra-Small, Low-Cost, 210MHz, Dual-SupplyOp Amps with Rail-to-Rail Outputs_______________________________________________________________________________________9Figure 4. Small-Signal Gain vs. Frequency with Load Capacitance and No Isolation ResistorFigure 5. Small-Signal Gain vs. Frequency with Load Capacitance and 27ΩIsolation ResistorPin Configurations (continued)Chip InformationMAX4350 TRANSISTOR COUNT: 86MAX4351 TRANSISTOR COUNT: 170M A X 4350/M A X 4351Ultra-Small, Low-Cost, 210MHz, Dual-Supply Op Amps with Rail-to-Rail OutputsPackage 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 .)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 ____________________11©2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.MAX4350/MAX4351Ultra-Small, Low-Cost, 200MHz, Dual-SupplyOp Amps with Rail-to-Rail OutputsPackage 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.)元器件交易网。
MAX481_MAX483_MAX485_MAX487_MAX1487_MAX490_MAX491_中文资料
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_____________________________ _概述MAX481、MAX483、MAX485、MAX487-MAX491以及MAX1487是用于RS-485与RS-422通信的低功耗收发器，每个器件中都具有一个驱动器和一个接收器。
MAX483、MAX487、MAX488以及MAX489具有限摆率驱动器，可以减小EMI ，并降低由不恰当的终端匹配电缆引起的反射，实现最高250k b p s 的无差错数据传输。
M A X 481、MAX485、MAX490、MAX491、MAX1487的驱动器摆率不受限制，可以实现最高2.5Mbps 的传输速率。
这些收发器在驱动器禁用的空载或满载状态下，吸取的电源电流在120(A 至500(A 之间。
另外，MAX481、MAX483与MAX487具有低电流关断模式，仅消耗0.1µA 。
所有器件都工作在5V 单电源下。
驱动器具有短路电流限制，并可以通过热关断电路将驱动器输出置为高阻状态，防止过度的功率损耗。
接收器输入具有失效保护特性，当输入开路时，可以确保逻辑高电平输出。
MAX487与MAX1487具有四分之一单位负载的接收器输入阻抗，使得总线上最多可以有128个M A X 487/MAX1487收发器。
使用MAX488-MAX491可以实现全双工通信，而MAX481、MAX483、MAX485、MAX487与MAX1487则为半双工应用设计。
_______________________________应用低功耗RS-485收发器低功耗RS-422收发器电平转换器用于EMI 敏感应用的收发器工业控制局域网____________________下一代器件的特性♦容错应用MAX3430: ±80V 故障保护、失效保护、1/4单位负载、+3.3V 、RS-485收发器MAX3440E-MAX3444E: ±15kV ESD 保护、±60V 故障保护、10Mbps 、失效保护、RS-485/J1708收发器♦对于空间受限应用MAX3460-MAX3464: +5V 、失效保护、20Mbps 、Profibus RS-485/RS-422收发器MAX3362: +3.3V 、高速、RS-485/RS-422收发器，采用SOT23封装MAX3280E-MAX3284E: ±15kV ESD 保护、52Mbps 、+3V 至+5.5V 、SOT23、RS-485/RS-422、真失效保护接收器MAX3293/MAX3294/MAX3295: 20Mbps 、+3.3V 、SOT23、RS-485/RS-422发送器♦对于多通道收发器应用MAX3030E-MAX3033E: ±15kV ESD 保护、+3.3V 、四路RS-422发送器♦对于失效保护应用MAX3080-MAX3089: 失效保护、高速(10Mbps)、限摆率RS-485/RS-422收发器♦对于低电压应用MAX3483E/MAX3485E/MAX3486E/MAX3488E/MAX3490E/MAX3491E: +3.3V 供电、±15kV ESD 保护、12Mbps 、限摆率、真正的RS-485/RS-422收发器MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487低功耗、限摆率、RS-485/RS-422收发器_____________________________________________________________________选择表19-0122; Rev 8; 10/03定购信息在本资料的最后给出。
LINEAR TECHNOLOGY LTC1474 LTC1475 数据手册
12SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V FB Feedback Voltage I LOAD = 50mA q 1.205 1.230 1.255V LTC1474/LTC1475V OUT Regulated Output Voltage I LOAD = 50mALTC1474-3.3/LTC1475-3.3q 3.234 3.300 3.366VLTC1474-5/LTC1475-5q 4.900 5.000 5.100V I FB Feedback Current q030nALTC1474/LTC1475 OnlyI SUPPLY No Load Supply Current (Note 3)I LOAD = 0 (Figure 1 Circuit)10µA ∆V OUT Output Voltage Line Regulation V IN = 7V to 12V, I LOAD = 50mA520mV Output Voltage Load Regulation I LOAD = 0mA to 50mA215mVOutput Ripple I LOAD = 10mA50mV P-P I Q Input DC Supply Current (Note 2)(Exclusive of Driver Gate Charge Current)Active Mode (Switch On)V IN = 3V to 18V100175µASleep Mode (Note 3)V IN = 3V to 18V915µAShutdown V IN = 3V to 18V, V RUN = 0V612µA R ON Switch Resistance I SW = 100mA 1.4 1.6ΩI PEAK Current Comp Max Current Trip Threshold R SENSE = 0Ω325400mAR SENSE = 1.1Ω707685mA V SENSE Current Comp Sense Voltage Trip Threshold q90100110mV V HYST Voltage Comparator Hysteresis5mV t OFF Switch Off-Time V OUT at Regulated Value 3.5 4.75 6.0µsV OUT = 0V65µs V LBI, TRIP Low Battery Comparator Threshold q 1.16 1.23 1.27V V RUN Run/ON Pin Threshold0.40.7 1.0V V LBI, OFF OFF Pin Threshold (LTC1475 Only)0.40.7 1.0V I LBO, SINK Sink Current into Pin 2V LBI = 0V, V LBO = 0.4V0.450.70mA I RUN, SOURCE Source Current from Pin 8V RUN = 0V0.40.8 1.2µA I SW, LEAK Switch Leakage Current V IN = 18V, V SW = 0V, V RUN = 0V0.0151µA I LBI, LEAK Leakage Current into Pin 3V LBI = 18V, V IN = 18V00.1µA I LBO, LEAK Leakage Current into Pin 2V LBI = 2V, V LBO = 5V00.5µA ELECTRICAL CHARACTERISTICS T A = 25°C, V IN = 10V, V RUN = open, R SENSE = 0, unless otherwise noted.The q denotes specifications which apply over the full operating temperature range.N ote 1: T J is calculated from the ambient temperature T A and power dissipation P D according to the following formulas:LTC1474CS8/LTC1475CS8: T J = T A + (P D • 110°C/W)LTC1474CMS8/LTC1475CMS8: T J = T A + (P D • 150°C/W)Note 2: Dynamic supply current is higher due to the gate charge being delivered at the switching frequency. See Applications Information.Note 3: No load supply current consists of sleep mode DC current (9µA typical) plus a small switching component (about 1µA for Figure 1 circuit) necessary to overcome Schottky diode and feedback resistor leakage.3456OPERATIO U(Refer to Functional Diagram)The LTC1474/LTC1475 are step-down converters with internal power switches that use Burst Mode operation to keep the output capacitor charged to the proper output voltage while minimizing the quiescent current. Burst Mode operation functions by using short “burst” cycles to ramp the inductor current through the internal power switch and external Schottky diode, followed by a sleep cycle where the power switch is off and the load current is supplied by the output capacitor. During sleep mode, the LTC1474/LTC1475 draw only 9µA typical supply current.At light loads, the burst cycles are a small percentage of the total cycle time; thus the average supply current is very low, greatly enhancing efficiency.Burst Mode OperationAt the beginning of the burst cycle, the switch is turned on and the inductor current ramps up. At this time, the internal current comparator is also turned on to monitor the switch current by measuring the voltage across the internal and optional external current sense resistors. When this volt-age reaches 100mV, the current comparator trips and pulses the 1-shot timer to start a 4.75µs off-time during which the switch is turned off and the inductor current ramps down. At the end of the off-time, if the output voltage is less than the voltage comparator threshold, the switch is turned back on and another cycle commences. To minimize supply current, the current comparator is turned on only during the switch-on period when it is needed to monitor switch current. Likewise, the 1-shot timer will only be on during the 4.75µs off-time period.The average inductor current during a burst cycle will normally be greater than the load current, and thus the output voltage will slowly increase until the internal volt-age comparator trips. At this time, the LTC1474/LTC1475go into sleep mode, during which the power switch is off and only the minimum required circuitry is left on: the voltage comparator, reference and low battery compara-tor. During sleep mode, with the output capacitor supply-ing the load current, the V FB voltage will slowly decrease until it reaches the lower threshold of the voltage com-parator (about 5mV below the upper threshold). The voltage comparator then trips again, signaling the LTC1474/LTC1475 to turn on the circuitry necessary to begin a new burst cycle.Peak Inductor Current ProgrammingThe current comparator provides a means for program-ming the maximum inductor/switch current for each switch cycle. The 1X sense MOSFET, a portion of the main power MOSFET, is used to divert a sample (about 5%) of the switch current through the internal 5Ω sense resistor. The current comparator monitors the voltage drop across the series combination of the internal and external sense resistors and trips when the voltage exceeds 100mV. If the external sense resistor is not used (Pins 6 and 7 shorted),the current threshold defaults to the 400mA maximum due to the internal sense resistor.Off-TimeThe off-time duration is 4.75µs when the feedback voltage is close to the reference; however, as the feedback voltage drops, the off-time lengthens and reaches a maximum value of about 65µs when this voltage is zero. This ensures that the inductor current has enough time to decay when the reverse voltage across the inductor is low such as during short circuit.Shutdown ModeBoth LTC1474 and LTC1475 provide a shutdown mode that turns off the power switch and all circuitry except for the low battery comparator and 1.23V reference, further reducing DC supply current to 6µA typical. The LTC1474’s run/shutdown mode is controlled by a voltage level at the RUN pin (ground = shutdown, open/high = run). The LTC1475’s run/shutdown mode, on the other hand, is controlled by an internal S/R flip-flop to provide pushbutton on/off control. The flip-flop is set (run mode) by a momen-tary ground at the ON pin and reset (shutdown mode) by a momentary ground at the LBI/OFF pin.Low Battery ComparatorThe low battery comparator compares the voltage on the LBI pin to the internal reference and has an open drain N-channel MOSFET at its output. If LBI is above the reference, the output FET is off and the LBO output is high impedance. If LBI is below the reference, the output FET is on and sinks current. The comparator is still active in shutdown.789APPLICATIO S I FOR ATIO W UU U C IN and C OUT SelectionAt higher load currents, when the inductor current is continuous, the source current of the P-channel MOSFET is a square wave of duty cycle V OUT /V IN . To prevent large voltage transients, a low ESR input capacitor sized for the maximum RMS current must be used. The maximum capacitor current is given by:C V V V V IN OUT IN OUTINRequired I =I RMS MAX −()[]12/This formula has a maximum at V IN = 2V OUT , where I RMS = I OUT /2. This simple worst-case condition is com-monly used for design because even significant deviations do not offer much relief. Note that capacitor manufacturer’s ripple current ratings are often based on 2000 hours of life.This makes it advisable to further derate the capacitor, or to choose a capacitor rated at a higher temperature than required. Do not underspecify this component. An addi-tional 0.1µF ceramic capacitor is also required on V IN for high frequency decoupling.The selection of C OUT is driven by the required effective series resistance (ESR) to meet the output voltage ripple and line regulation requirements. The output voltage ripple during a burst cycle is dominated by the output capacitor ESR and can be estimated from the following relation:25mV < ∆V OUT, RIPPLE = ∆I L • ESRwhere ∆I L ≤ I PEAK and the lower limit of 25mV is due to the voltage comparator hysteresis. Line regulation can also vary with C OUT ESR in applications with a large input voltage range and high peak currents.ESR is a direct function of the volume of the capacitor.Manufacturers such as Nichicon, AVX and Sprague should be considered for high performance capacitors. The OS-CON semiconductor dielectric capacitor available from SANYO has the lowest ESR for its size at a somewhat higher price. Typically, once the ESR requirement is satis-fied, the capacitance is adequate for filtering. For lower current applications with peak currents less than 50mA,10µF ceramic capacitors provide adequate filtering and are a good choice due to their small size and almostnegligible ESR. AVX and Marcon are good sources for these capacitors.In surface mount applications multiple capacitors may have to be paralleled to meet the ESR or RMS current handling requirements of the application. Aluminum elec-trolytic and dry tantalum capacitors are both available in surface mount configurations. In the case of tantalum, it is critical that the capacitors are surge tested for use in switching power supplies. An excellent choice is the AVX TPS series of surface mount tantalums, available in case heights ranging from 2mm to 4mm. Other capacitor types include SANYO OS-CON, Nichicon PL series and Sprague 595D series. Consult the manufacturer for other specific recommendations.To avoid overheating, the output capacitor must be sized to handle the ripple current generated by the inductor. The worst-case ripple current in the output capacitor is given by:I RMS = I PEAK /2Once the ESR requirement for C OUT has been met, the RMS current rating generally far exceeds the I RIPPLE(P-P)requirement.Efficiency ConsiderationsThe efficiency of a switching regulator is equal to the output power divided by the input power times 100%. It is often useful to analyze individual losses to determine what is limiting efficiency and which change would produce the most improvement. Efficiency can be expressed as:Efficiency = 100% – (L1 + L2 + L3 + ...)where L1, L2, etc. are the individual losses as a percentage of input power.Although all dissipative elements in the circuit produce losses, three main sources usually account for most of the losses in LTC1474/LTC1475 circuits: V IN current, I 2R losses and catch diode losses.1.The V IN current is due to two components: the DC bias current and the internal P-channel switch gate charge current. The DC bias current is 9µA at no load and increases proportionally with load up to a constant 100µA during continuous mode. This bias current is so10111213141516171819Information furnished by Linear Technology Corporation is believed to be accurate and reliable.However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.20© Linear Technology Corporation1630 McCarthy Blvd., Milpitas, CA 95035-7417 q (408) 432-1900FAX: (408) 434-0507 q TELEX: 499-3977 q 。
数字可编程电容器MAX1474
增大电容可调范围电路
通过几个MAX1474并联，可以增加电容的 可调范围，除MAX1474外，从MAX1450到 MAX1478还有许多数字可编程电容器可供 选择。这种数字编程接口简单易用的电可调 电容器，容值调节电路简单，在整个温度范 围内均可保证高精度。
MAX1474总结
优点：数字可编程电容器不需要像传统可变电容器那样
数字可编程电容器MAX1474 数字可编程电容器MAX1474
班级: 报告人: 成员:
清华大学
电容器按照结构分为：固定电容器、可变电容 器、微调电容器
固定电容器：电容值固定的电容器 可变电容器：电容量可在一定范围内调节的电容器 微调电容器：电容量可在某一小范围内调整，并可在调整 后固定于某个电容值的电容器
报告完毕
失调补偿电路
失调补偿电路通过两电容 的差值不断调控MAX1474， 从而使两者的电容值趋于 相等。
在大多数应用中，需要检测这些电容值之差，像压力、加速度和 温度等电容性传感器，通常由2只电容器组成。其中1只电容器用 作参考电容，另1只电容器的容值随传感功能改变。由于制造容差 ，2电容之间存在失调，借助MAX1474很容易使失调得到补偿。
Q值增强电路
电容Q值：在某一频率下，电容器损耗 比上电容器存储功率（无用功功率）。 电容的品质因数Q越高越好！
由于电可调电容器带多路利用串联电阻器，其品质因数Q较 低。例如：在315MHz和5欧的串联电阻下，10pF电容器的Q约 为10。用1只高Q的外部电容器（36pF）与电可调电容器并联， 可得到非常高的Q值。该拓扑结构在带1只27nH的谐振电感器时 ，频率调节范围从314MHz到319MHz，每级步升160kHz。
电容器在电子线路的作用概括为： 通交流，阻直流，滤波，旁路。耦合等
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General DescriptionThe MAX1474 is a fine-line (geometry) electronically trim-mable capacitor (FLECAP) programmable through a simple digital interface. There are 32 programmable capacitance values ranging from 6.4pF to 13.3pF in 0.22pF increments (Table 1). The quartz dielectric capacitance is highly stable and exhibits a very low volt-age coefficient. It has virtually no dielectric absorption and has a very low temperature drift coefficient (<33ppm/°C). The MAX1474 is programmed through two digital interface pins, which have Schmidt triggers and pulldown resistors to secure capacitance programming.CustomizationMaxim can customize the MAX1474 for specific high-volume applications. Contact Maxim for further informa-tion.ApplicationsPost-Trim of Low-Cost Regenerative Receivers Tunable RF StagesLow-Cost, Low-Temperature Drift Oscillators Garage Door Openers Keyless EntryIndustrial Wireless Control Capacitive Sensor Trimming RFID TagsFeatureso Tiny SC70 Package (1.1mm x 2.2mm x 2.4mm) o High-Performance Electronically Trimmable Capacitance o Very Simple Digital Interfaceo Eliminates the Need for Mechanical Tuning o Enabling Technology for Low-Cost Production Line Automation o Fully Static Operation After Programming (No Switching)MAX1474Miniature Electronically Trimmable Capacitor________________________________________________________________Maxim Integrated Products 1Ordering Information19-1948; Rev 1; 3/01Functional DiagramPin ConfigurationFor pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at .M A X 1474Miniature Electronically Trimmable Capacitor 2_______________________________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL CHARACTERISTICSStresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Supply Voltage, V DD to V SS ..................................... -0.3V to +6V All Other Pins...................................(V SS - 0.3V) to (V DD + 0.3V)RMS Current into Any Pin....................................................50mA Continuous Power Dissipation (T A = +70°C)6-Pin SC70 (derate 3.1mW/°C above +70°C).............245mWOperating Temperature RangeMAX1474AXT................................................-40°C to +125°C Storage Temperature Range.............................-65°C to +150°C Junction Temperature......................................................+150°C Lead Temperature (soldering, 10s).................................+300°CMAX1474Miniature Electronically Trimmable Capacitor_______________________________________________________________________________________310.9010.9310.9210.9110.9510.9410.9910.9810.9710.9611.00-40-1510356085110125CAPACITANCE vs. TEMPERATURETEMPERATURE (°C)C S (p F )14.014.415.214.815.616.0021345CAPACITANCE vs. VOLTAGE(SINGLE ENDED)VOLTAGE (V)C S (p F )10.9010.9511.0511.0011.10-5-3-2-1-412345VOLTAGE (V)C S (p F )CAPACITANCE vs. VOLTAGE(DIFFERENTIAL)6936331512211827243039503505006502008009501100EFFECTIVE CAPACITANCEvs. FREQUENCYFREQUENCY (MHz)C A P A C I T A N C E (p F )101001000QUALITY FACTOR vs. FREQUENCYM A X 1474 t o c 05FREQUENCY (MHz)Q1101000428612101418162068971011121314QUALITY FACTOR vs. CAPACITANCEM A X 1474 t o c 06CAPACITANCE (pF)QTypical Operating Characteristics(V DD = +5V, V SS = 0, T A = +25°C, unless otherwise noted.)80090085010009501050110011501200081241620242832SELF-RESONANTFREQUENCY vs. DAT PULSESM A X 1474 t o c 07DAT PULSESS R F (M H z )SMITH CHART:0 DAT PULSESf 1 = 1200MHzM A X 1474Detailed DescriptionThe MAX1474 consists of a binary-weighted array of capacitors that can be switched in and out of parallel to provide 32 monotonic steps. The switches implement-ed allow the DC bias of either terminal of the capacitor to be anywhere from ground to the supply voltage.There is no inherent polarity. The signal swing range is limited to 300mV above V DD and 300mV below V SS .Therefore, if a large-signal swing range is desired, care must be taken to bias the terminal(s) requiring high swing capability near midsupply.If the capacitance is measured differentially from one terminal to the other, the greatest min/max ratio of the binary array can be realized, allowing tuning from0.42pF to 10.9pF in 0.34pF steps. If one terminal is grounded, and the capacitance is measured to ground,the parasitics inherent in the package will become lumped with the switched array, allowing tuning from 6.4pF to 13.3pF in 0.22pF steps. When using the MAX1474, it is recommended for optimal performance to connect the CM terminal to the lowest impedance node (i.e., ground or supply if possible) and CP to the higher impedance node (i.e., the resonant node in a ground-referenced LC tank circuit).Digital InterfaceThe digital interface sets the desired capacitance value. There are only two pins, EN and DAT, required for this operation. EN is an active-high control signal.Miniature Electronically Trimmable Capacitor 4_______________________________________________________________________________________Typical Operating Characteristics (continued)(V DD = +5V, V SS = 0, T A = +25°C, unless otherwise noted.)SMITH CHART:15 DAT PULSESf 1 = 962MHz Pin DescriptionSMITH CHART:31 DAT PULSESf 1 = 848MHzMAX1474Miniature Electronically Trimmable CapacitorWhile EN is asserted, the internal counter counts posi-tive edges of DAT. The number of sequential pulses on DAT determines the capacitance setting. As EN is de-asserted, the counter value is latched into the capaci-tance control registers first, and then the counter is set to zero. The programmed capacitance value then appears between CP and CM. During the period when EN is asserted, the capacitance value between CP and CM stays unchanged. Figure 1 is a digital timing dia-gram.Q Enhancement CircuitSince the capacitors have the multiplexer series resis-tance associated with them, the quality factor of the trimmable capacitors is not high. For example, a 10pF capacitor only has a theoretical Q of about 10 at 315MHz with 5Ωseries resistance. As in Figure 2, an impedance transformer-like circuit is needed to over-come this low Q. With this circuit, a much higher Q is achievable using high-Q external capacitors. This con-figuration allows a tuning range of approximately 314MHz to 319MHz with 160kHz steps when resonated with a 27nH inductor. Figure 2 shows a Q enhancement circuit.Startup SequenceThe MAX1474 must be programmed before use. When powered up, the following sequence must occur:•Deassert both EN and DAT.•Assert EN.•Send pulses on DAT. The total number of pulses determines the capacitance value (Table 1).•Deassert EN.Applications InformationThe MAX1474 offers users a wide range of applica-tions, including trimming of regenerative receivers,oscillators, RFID tags, and capacitive sensors. A capacitive sensor is usually made of two capacitors.One capacitor (CM) changes with the sensed function,such as pressure, acceleration, or humidity. The sec-ond capacitor (CR) is used as a reference capacitance that does not vary with the sensed function. In most applications, it is needed to detect the difference between these capacitance values. Due to manufactur-ing tolerances, there are normally offsets between CM and CR, which can easily be nulled out by the FLECAP as shown in Figure 4.To increase the adjustment capacitance range, several FLECAPs can be placed in parallel. Several capacitors can be tied together to increase the number of steps or the resolution, as shown in Figures 5a and 5b.The FLECAP zero step differential capacitance is low,typically 0.42pF. The parasitic capacitances are the reason for the 6pF of input capacitance and the decrease in range when configured as a single-ended capacitor. The MAX1474 is an excellent choice in appli-cations where only differential capacitance matters._______________________________________________________________________________________5M A X 1474Miniature Electronically Trimmable Capacitor 6_______________________________________________________________________________________Figure 1. Digital Timing DiagramTest Circuits/Timing DiagramsFigure 3a. Capacitance vs. Voltage (Single Ended)MAX1474Miniature Electronically Trimmable CapacitorFigure 3b. Capacitance vs. Voltage (Differential)Figure 5b. Increasing Capacitance Range and ResolutionFigure 4. Electronic Offset TrimmingFigure 5a. Increasing Capacitance RangeTest Circuits/Timing Diagrams (continued)_______________________________________________________________________________________7Chip InformationTRANSISTOR COUNT: 634M A X 1474Miniature Electronically Trimmable Capacitor Maxim cannot assume responsib ility for use of any circuitry other than circuitry entirely emb odied 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.8_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600©2001 Maxim Integrated ProductsPrinted USAis a registered trademark of Maxim Integrated Products.Package Information。