* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download MAX483CUA-T中文资料
Survey
Document related concepts
Flip-flop (electronics) wikipedia , lookup
Pulse-width modulation wikipedia , lookup
Power inverter wikipedia , lookup
Stray voltage wikipedia , lookup
Variable-frequency drive wikipedia , lookup
Current source wikipedia , lookup
Voltage optimisation wikipedia , lookup
Mains electricity wikipedia , lookup
Alternating current wikipedia , lookup
Transmission line loudspeaker wikipedia , lookup
Voltage regulator wikipedia , lookup
Two-port network wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Schmitt trigger wikipedia , lookup
Power electronics wikipedia , lookup
Switched-mode power supply wikipedia , lookup
Buck converter wikipedia , lookup
Transcript
文档下载 免费文档下载 http://www.wendangwang.com/ 本文档下载自文档下载网,内容可能不完整,您可以点击以下网址继续阅读或下载: http://www.wendangwang.com/doc/fef468fd14224c89cfe93682 MAX483CUA-T 中文资料 19-0122; Rev 8; 10/03 Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers General Description __Next Generation Device Features The MAX481, MAX483, MAX485, MAX487–MAX491, andMAX1487 are low-power transceivers for RS-485 and RS-?For Fault-Tolerant Applications 422 communication. Each part contains one driver and oneMAX3430: ±80V Fault-Protected, Fail-Safe, 1/4receiver. The MAX483, MAX487, MAX488, and MAX489Unit Load, 3.3V, RS-485 Transceiver feature reduced slew-rate drivers that minimize EMI andMAX3440E–MAX3444E: ±15kV ESD-Protected,reduce reflections caused by improperly terminated cables,±60V Fault-Protected, 10Mbps, Fail-Safe, thus allowing error-free data transmission up to 250kbps.The driver slew rates of the MAX481, MAX485, MAX490,RS-485/J1708 Transceivers MAX491, and MAX1487 are not limited, allowing them to?For Space-Constrained Applications 文档下载 免费文档下载 http://www.wendangwang.com/ transmit up to 2.5Mbps. MAX3460–MAX3464: 5V, Fail-Sahttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682fe, 20Mbps,These transceivers draw between 120?A and 500?A ofProfibus RS-485/RS-422 Transceivers supply current when unloaded or fully loaded with disabledMAX3362: 3.3V, High-Speed, RS-485/RS-422drivers. Additionally, the MAX481, MAX483, and MAX487Transceiver in a SOT23 Package have a low-current shutdown mode in which they consumeMAX3280E–MAX3284E: ±15kV ESD-Protected,only 0.1?A. All parts operate from a single 5V supply. 52Mbps, 3V to 5.5V, SOT23, RS-485/RS-422,Drivers are short-circuit current limited and are protectedTrue Fail-Safe Receivers against excessive power dissipation by thermal shutdowncircuitry that places the driver outputs into a high-imped-MAX3293/MAX3294/MAX3295: 20Mbps, The receiver input has a fail-safe feature 3.3V,ance state. thatSOT23, RS-855/RS-422 Transmittersguarantees a logic-high output if the input is open circuit.?For Multiple Transceiver Applications Thttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682he feature quarter-unit-loadMAX3030E–MAX3033E: MAX487 and MAX1487 ±15kV ESD-Protected,receiver input impedance, allowing up to 128 MAX487/ 3.3V, Quad RS-422 TransmittersMAX1487 transceivers on the bus. Full-duplex communi-?For Fail-Safe Applications cations are obtained using the MAX488–MAX491, whilethe MAX481, MAX483, MAX485, MAX487, and MAX1487MAX3080–MAX3089: half-duplex applications. Fail-Safe, High-Speedare designed for 文档下载 免费文档下载 http://www.wendangwang.com/ (10Mbps), Slew-Rate-Limited RS-485/RS-422Transceivers ________________________Applications ?For Low-Voltage Applications Low-Power RS-485 TransceiversMAX3483E/MAX3485E/MAX3486E/MAX3488E/Low-Power RS-422 TransceiversMAX3490E/MAX3491E: 3.3V Powered, ±15kVLevel Translators ESD-Protected, 12Mbps, Slew-Rate-Limited,True RS-485/RS-422 Transceivers Transceivers for EMI-Sensitive ApplicationsIndustrial-Control Local Area Networks Ordering Informahttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682tion appears at end of data sheet. ______________________________________________________________Selection Table For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 Low-Power, Slew-Rate-LimitedRS-485/RS-422 TransceiversMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 ABSOLUTE MAXIMUM RATINGS Supply Voltage 文档下载 免费文档下载 http://www.wendangwang.com/ (VCC).............................................................12VControl Input Voltage (RE, DE)...................-0.5V to (VCC (DI).............................-0.5V to (VCC B)...................................-8V to B).................................-8V (RO).....................-0.5V 0.5V)Driver Input Voltage 0.5V)Driver Output Voltage (A, 12.5VReceiver Input Voltage (A, to 12.5VReceiver to (VCC Output 0.5V)Continuous Dihttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682ssipation (TA= 8-Pin Plastic DIP (derate 9.09mW/°C above (derate 10.00mW/°C above Voltage Power 70°C) 70°C)....727mW14-Pin Plastic DIP 70°C)..800mW8-Pin SO (derate 5.88mW/°C above 70°C).................471mW 14-Pin SO (derate 8.33mW/°C above 4.1mW/°C above 70°C)...............667mW8-Pin ?MAX (derate 70°C)..............830mW8-Pin CERDIP (derate 8.00mW/°C above 70°C).........640mW14-Pin CERDIP (derate 9.09mW/°C above 70°C).......727mWOperating Temperature Ranges MAX4_ _C_ _/MAX1487C_ A...............................0°C to _/MAX1487E_ A.............................-40°C 85°CMAX4__MJ_/MAX1487MJA...........................-55°C Temperature Range.............................-65°C to to 70°CMAX4__E_ to 125°CStorage 160°CLead Temperature (soldering, 10sec)............................. 300°C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are strhttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682ess ratings only, and functionaloperation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure toabsolute maximum rating conditions for extended periods may affect device reliability. 文档下载 免费文档下载 http://www.wendangwang.com/ DC ELECTRICAL CHARACTERISTICS (VCC= 5V ±5%, TA= TMINto TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER Differential Driver Output (no load)Differential Driver Output(with load) Change in Magnitude of DriverDifferential Output Voltage forComplementary Output StatesDriver Common-Mode OutputVoltage Change in Magnitude of DriverCommon-Mode Output Voltagefor Complementary Output StatesInput High VoltageInput Low VoltageInput Current SYMBOLVOD1VOD2?VODVOC?VODVIHVILIIN1 R = 50?(RS-422) R = 27?(RS-485), Figure 4R = 27?or 50?, Figure 4R = 27?or 50?, Figure 4R = 27?or 50?, Figure 4DE, http://www.wendangwang.com/doc/fef468fd14224c89cfe93682DI, REDE, DI, REDE, DI, REDE = 0V; VCC= 0V or 5.25V,all devices exceptMAX487/MAX1487 MAX487/MAX1487, DE = 0V, VCC= 0V or 5.25V Receiver Differential ThresholdVoltage 文档下载 免费文档下载 http://www.wendangwang.com/ Receiver Input HysteresisReceiver Output High VoltageReceiver VoltageThree-State (high impedance)Output Current at Receiver VTH?VTHVOHVOLIOZR -7V ≤VCM≤12VVCM= 0V IO= -4mA, VID= 200mVIO = 4mA, VID= -200mV0.4V ≤VO≤2.4V -7V ≤VCM≤12V, all devices exceptMAX487/MAX1487 -7V ≤VCM ≤12V, MAX487/MAX1487 12483.5 0.4±1 VIN= 12VVIN= -7VVIN= 12VVIN= -7V -0.2 70 2.0 0.8±21.0 mA Output Low 文档下载 免费文档下载 http://www.wendangwang.com/ -0.80.25-0.20.2 mAVmVVV?Ak?k? 21.5 50.230.2 CONDITIONS MIN TYP MAX5 UNITSVVVVVVV?A Input Current(A, B) IIN2 Receiver Input Resistancehttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682RIN 2_______________________________________________________________________________ ________ Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers 文档下载 免费文档下载 http://www.wendangwang.com/ DC ELECTRICAL CHARACTERISTICS (continued) (VCC= 5V ±5%, TA= TMINto TMAX, unless otherwise noted.) (Notes 1, 2) SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487 (VCC= 5V ±5%, TA= TMINto TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER SYMBOLCONDITIONSMINTYPMAXUNITSDriver Input to OutputtPLHFigures 6 and 8, RDIFF= 54?, 103060tPHL CL1= CL2= 100pF103060nsDriver Output Skew to OutputtSKEWFigures 6 and 8, RDIFF= 54?, CL1= CL2= 100pF510nsFigures 6 and 8, MAX481, MAX485, MAX148731540Driver Rise or Fall TimetR, tFRDIFF= 54?,MAX490C/E, MAX491C/E51525nsCL1= CL2= 100pFMAX490M, MAX491M 3 1540Driver Enable to Output HightZHFigures 7 and 9, CL= 100pF, S2 closed4070nshttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682Driver Enable to Output LowtZLFigures 7 and 9, CL= 100pF, S1 closed4070nsDriver Disable Time from LowtLZFigures 7 and 9, CL= 15pF, S1 closed4070nsDriver Disable Time from HightHZFigures 7 and 9, CL= 15pF, S2 closed 4070nsFigures 6 and 10,MAX481, MAX485, MAX1487 文档下载 免费文档下载 http://www.wendangwang.com/ 2090200Receiver Input to Output tPLH, tPHLRDIFF= 54?,MAX490C/E, MAX491C/E 2090150ns CL1= CL2= 100pFMAX490M, MAX491M20 90200 |tPLH- tPHL|Differential Receiver Skew tSKDFigures 6 and 10, RDIFF= 54?,CL1= CL2= 100pF 13nsReceiver Enable to Output LowtZLFigures 5 and 11, CRL= 15pF, S1 closed2050nsReceiver Enable to Output HightZHFigures 5 and 11, CRL= 15pF, S2 closed2050nsReceiver Disable Time from LowtLZFigures 5 and 11, CRL= 15pF, S1 closed2050nsReceiver Disable Time from HightHZFigures 5 and 11, CRL= 15pF, S2 closed 2050nsMaximum Data RatefMAX2.5MbpsTime to Shutdown tSHDNhttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682 MAX481 (Note 5) 50200 600ns 文档下载 免费文档下载 http://www.wendangwang.com/ ________________________________________________________________________________ _______3 MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 Low-Power, Slew-Rate-LimitedRS-485/RS-422 TransceiversMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487 (continued) (VCC= 5V ±5%, TA= TMINto TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER SYMBOL CONDITIONS Figures 7 and 9, CL= 100pF, S2 closedFigures 7 and 9, CL= 100pF, S1 closedFigures 5 and 11, CL= 15pF, S2 closed,A - B = 2V Figures 5 and 11, CL= 15pF, S1 closed,B - A = 2V MIN TYP4040300300 MAX10010010001000 文档下载 免费文档下载 http://www.wendangwang.com/ UNITSnsnsnsns Driver Enable from Shutdown to tZH(SHDN) Output High (MAX481) Driver Enable from Shutdown to thttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682ZL(SHDN) Output Low (MAX481) Receiver Enable from Shutdown tZH(SHDN) to Output High (MAX481) Receiver Enable from Shutdown tZL(SHDN) to Output Low (MAX481) SWITCHING CHARACTERISTICS—MAX483, MAX487/MAX488/MAX489 (VCC= 5V ±5%, TA= TMINto TMAX, unless otherwise noted.) (Notes 1, 2) 文档下载 免费文档下载 http://www.wendangwang.com/ PARAMETER Driver Input to OutputDriver Output Skew to OutputDriver Rise or Fall TimeDriver Enable to Output HighDriver Enable to Output LowDriver Disable Time from LowDriver Disable Time from HighReceiver Input to Output SYMBOLtPLHtPHLtSKEWtR, tFtZHtZLtLZtHZtPLHtPHLtSKDtZLtZHtLZtHZfMAXtSHDNtZH(SHDN)tZL(SHDN)tZH(SHDN)tZL(SH DN) CONDITIONS Figures 6 and 8, RDIFF= 54?,CL1= CL2= 100pF Figures 6 and 8, RDIFF= 54?,CL1= CL2= 100pF Figures 6 and 8, RDIFF= 54?,CL1= CL2= 100pF Figures 7 and 9, CL= 100pF, S2 closedFiguhttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682res 7 and 9, CL= 100pF, S1 closedFigures 7 and 9, CL= 15pF, S1 closedFigures 7 and 9, CL= 15pF, S2 closedFigures 6 and 10, RDIFF= 54?,CL1= CL2= 100pF Figures 6 and 10, RDIFF= 54?,CL1= CL2= 100pF Figures 5 and 11, CRL= 15pF, S1 closedFigures 5 and 11, CRL= 15pF, S2 closedFigures 5 and 11, CRL= 15pF, S1 closedFigures 5 and 11, CRL= 15pF, S2 closedtPLH, tPHL MAX483/MAX487, Figures 7 and 9,CL= 100pF, S1 closed 文档下载 免费文档下载 http://www.wendangwang.com/ MAX483/MAX487, Figures 5 and 11,CL= 15pF, S2 closed MAX483/MAX487, Figures 5 and 11,CL= 15pF, S1 closed 25050 200 6002000200025002500 250250250300300250250 10020202020 50505050 MIN250250 TYP800800100 MAX200020008002000200020003000300020002000 UNITSnsnsnsnsnsnsnsnsnsnsnsnsnskbpsnsnsnsnsns ItPLH- tPHLIDifferential Receiver Skew Receiver Enable to Output LowReceiver http://www.wendangwang.com/doc/fef468fd14224c89cfe93682to Output Enable HighReceiver 文档下载 免费文档下载 http://www.wendangwang.com/ Disable Time from LowReceiver Disable Time from HighMaximum Data RateTime to Shutdown Driver Enable from Shutdown toOutput High Driver Enable from Shutdown toOutput Low Receiver Enable from Shutdownto Output High Receiver Enable from Shutdownto Output Low 4_______________________________________________________________________________ ________ Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers NOTES FOR ELECTRICAL/SWITCHING CHARACTERISTICS Note 1:All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to device ground unless otherwise specified. Note 2:All typical specifications are given for VCC= 5V and TA= 25°C. Note 3:Supply current specification is valid for loaded transmitters when DE = 0V.Note 4:Applies to peak current. See Typical Operatinghttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682 Characteristics. Note 5:The MAX481/MAX483/MAX487 are put into shutdown by bringingREhigh and DE low. 文档下载 免费文档下载 http://www.wendangwang.com/ If the inputs are in this state for less than 50ns, the parts are guaranteed not to enter shutdown. If the inputs are in this state for at least 600ns, the parts areguaranteed to have entered shutdown. See Low-Power Shutdown Modesection. __________________________________________Typical Operating Characteristics (VCC= 5V, TA = 25°C, unless otherwise noted.) OUTPUT CURRENT vs. OUTPUT CURRENT vs. RECEIVER OUTPUT HIGH VOLTAGE vs. RECEIVER OUTPUT LOW VOLTAGE RECEIVER OUTPUT HIGH VOLTAGE TEMPERATURE 451 -202 00-4.8 -18148X-18440AXMAM4.6) 文档下载 免费文档下载 http://www.wendangwang.com/ ) ) -16VA35A( 4.4mmE((G -14T30TANNT4.2EE-12LRROR25RV 4.0UU-10HCCG T15TUUUP3.6OT10O-6-4UO3.45-23.200 3.0 http://www.wendangwang.com/doc/fef468fd14224c89cfe93682 0.5 1.0 1.5 2.0 2.51.52.02.53.03.54.04.55.0-50-250255075100125 OUTPUT LOW VOLTAGE (V)OUTPUT HIGH VOLTAGE (V)TEMPERATURE (°C) RECEIVER OUTPUT LOW VOLTAGE vs. DRIVER OUTPUT CURRENT vs.DRIVER DIFFERENTIAL OUTPUT VOLTAGE TEMPERATURE IT20TH3.8UU-8 PPT 文档下载 免费文档下载 http://www.wendangwang.com/ DIFFERENTIAL OUTPUT VOLTAGE vs. TEMPERATURE 0.9905 2.4 0-10.88480X) AMV(2.3 ) EVG() A 0.7EA70T2.2GmLA( OT0.6TV2.1 LN60OETVRUP2.0 0.5WR50UTOCUL0.4 O T40T L1.9UUPAIP0.3T30TTN1.8UUEO0.2O20RE1.7FF0.110ID1.600 1.5 -50 -25 25 文档下载 免费文档下载 http://www.wendangwang.com/ 50 75 10012500.51.01.52.02.53.03.54.04.5-50 -25 25 50 75 100 125 TEMPERATURE (°C)DIFFERENTIAL OUTPUT VOLTAGE (V) TEMPERATURE (°C) _________________________http://www.wendangwang.com/doc/fef468fd14224c89cfe93682 ______________________________________________________________5 MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 Low-Power, Slew-Rate-LimitedRS-485/RS-422 文档下载 免费文档下载 http://www.wendangwang.com/ TransceiversMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 ____________________________Typical Operating Characteristics (continued) (VCC= 5V, TA = 25°C, unless otherwise noted.) OUTPUT CURRENT vs.DRIVER OUTPUT LOW VOLTAGE MAX481-07 OUTPUT CURRENT vs.DRIVER OUTPUT HIGH VOLTAGE MAX481-08 MAX481/MAX485/MAX490/MAX491SUPPLY CURRENT vs. TEMPERATURE 140120OUTPUT CURRENT (mA)1008060402000 2 4 6 8 10 -120-100OUTPUT CURRENT (mA) 文档下载 免费文档下载 http://www.wendangwang.com/ -80-60-40-200 600500SUPPLY CURRENT (?A)400300 2001000 12-7-6-5-4-3-2-1012345-50-250255075100125 OUTPUT LOW VOLTAGE (V)OUTPUT HIGH VOLTAGE (V)TEMPERATURE (°C) MAX483/MAX487–MAX48http://www.wendangwang.com/doc/fef468fd14224c89cfe936829 SUPPLY CURRENT vs. TEMPERATURE MAX1487 SUPPLY CURRENT vs. TEMPERATURE 600500SUPPLY CURRENT (?A)400300 600500SUPPLY CURRENT (?A)400300 200100 200100 0-50 -25 文档下载 免费文档下载 http://www.wendangwang.com/ 25 50 75 100 125 TEMPERATURE (°C) -60-40-20 02040 6080100120140 TEMPERATURE (°C) 6_______________________________________________________________________________ ________ Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers ______________________________________________________________Pin Description 文档下载 免费文档下载 http://www.wendangwang.com/ Figure 1. MAX481/MAX483/MAX485/MAX487/MAX1487 Pin Configuration and Typical Operating Circuit ________________________________________________________________________________ _______ 7 MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487://www.wendangwang.com/doc/fef468fd14 224c89cfe93682par Low-Power, Slew-Rate-LimitedRS-485/RS-422 TransceiversMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 Figure 2. MAX488/MAX490 Pin Configuration and Typical Operating Circuit Figure 3. MAX489/MAX491 Pin Configuration and Typical Operating Circuit __________Applications Information The MAX481/MAX483/MAX485/MAX487–MAX491 andMAX1487 are low-power transceivers for RS-485 and RS-422 communications. The MAX481, MAX485, MAX490,MAX491, and MAX1487 can transmit and receive at datarates up to 2.5Mbps, while the MAX483, MAX487,MAX488, and MAX489 are specified for data rates up to250kbps. The MAX488–MAX491 are full-duplex trans-ceivers while the MAX481, MAX483, MAX485, MAX487,and MAX1487 are half-duplex. In addition, Driver EnableMAX481, MAX483, MAX485, MAX487, MAX489,MAX491, and MAX1487. When disabled, the driver andreceiver outputs are high impedance. 8 文档下载 免费文档下载 http://www.wendangwang.com/ MAX487/MAX1487: 128 Trahttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682nsceivers on the Bus The 48k?, 1/4-unit-load receiver input impedance of theMAX487 and MAX1487 allows up to 128 transceiverson a bus, compared to the 1-unit load (12k?inputimpedance) of standard RS-485 drivers (32 trans-ceivers maximum). Any combination of MAX487/MAX1487 and other RS-485 transceivers with a total of32 unit loads or less can be put on the bus. TheMAX481/MAX483/MAX485 and MAX488–MAX491 havestandard 12k?Receiver Input impedance. ________________________________________________________________________________ _______ Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers _________________________________________________________________Test Circuits Figure 4. Driver DC Test LoadFigure 5. Receiver Timing Test Load Figure 6. Driver/Receiver Timing Test CircuitFigure 7. Driver Timing Test Load MAX483/MAX487/MAX488/MAX489: monics with large arhttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682e amplitudes evident. Figure 13Reduced EMI and Reflections shows the same information displayed for a MAX483,The MAX483 and MAX487–MAX489 are slew-rate limit-MAX487, MAX488, or MAX489 transmitting under theed, minimizing EMI 文档下载 免费文档下载 http://www.wendangwang.com/ and reducing reflections caused bysame conditions. Figure 13’s high-frequency harmonicsimproperly terminated cables. Figure 12 shows the dri-have much lower amplitudes, and the potential for EMIver output waveform and its Fourier analysis of ais significantly reduced. 150kHz signal transmitted by a MAX481, MAX485,MAX490, MAX491, or MAX1487. High-frequency har- ________________________________________________________________________________ _______9 MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 Low-Power, Slew-Rate-LimitedRS-485/RS-422 TransceiversMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 _______________________________________________________Switching Waveforms Fhttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682igure 8. Propagation Delays Figure 9. Driver Enable and Disable Times (except MAX488 andMAX490) Figure 10. Receiver Propagation Delays Figure 11. Receiver Enable and Disable Times (except MAX488and MAX490) _________________Function Tables (MAX481/MAX483/MAX485/MAX487/MAX1487) Table 1. Transmitting Driver 文档下载 免费文档下载 http://www.wendangwang.com/ Table 2. Receiving 10 Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers 10dB/div 10dB/div 0Hz 5MHz 0Hz 5MHz 500kHz/div 500kHz/div Figure 12. Driver Output Waveform and FFT Plot of MAX481/Figure 13. Driver Output Waveform and FFT Plot of MAX483/MAX485/MAX490/MAX491/MAX1487 Transmitting a 150kHzMAX487–MAX489 Transmitting a 150kHz Signal Signal Low-Power Shutdown ModeDriver Output Protection 文档下载 免费文档下载 http://www.wendangwang.com/ (MAX481/MAX483/MAX487) Excessive output current and phttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682ower dissipation causedA low-power shutdown mode is initiated by bringingby faults or by bus contention are prevented by twoboth REhigh and DE low. The devices will not shutmechanisms. A foldback current limit on the outputdown unless both the driver and receiver are disabled.stage provides immediate protection against short cir-In shutdown, the devices typically draw only 0.1?A ofcuits over the whole common-mode voltage range (seesupply current. Typical Operating Characteristics). In addition, a ther-REand DE may be driven simultaneously; the parts aremal shutdown circuit forces the driver outputs into aguaranteed not to enter shutdown if REis high and DEhigh-impedance state if the die temperature risesis low for less than 50ns. If the inputs are in this stateexcessively. for at least 600ns, the parts are guaranteed to entershutdown. Propagation Delay Many digital encoding schemes depend http://www.wendangwang.com/doc/fef468fd14224c89cfe93682differ-For MAX483, and MAX487, the tZHandence between the driver on the the MAX481, and receiver propagationtZLenable times assume the part was not in the low-delay times. Typical propagation delays are shown inpower shutdown state (the MAX485/MAX488–MAX491Figures 15–18 using Figure 14’s test circuit. and MAX1487 can not be shut down). The tand tZH(SHDN)ZL(SHDN)enable times assume the 文档下载 免费文档下载 http://www.wendangwang.com/ parts were shutThe difference in receiver delay times, | tPLH- tdown (see Electrical Characteristics). typically under 13ns for the MAX481, MAX485,PHL|, isMAX490, MAX491, and MAX1487 and is typically lessIt takes the drivers and receivers longer to becomethan 100ns for the MAX483 and MAX487–MAX489.enabled from the low-power shutdown state(tThe driver skew times are typically 5ns (10ns max) for(tZH(SHDN), tZL(SHDN)) than from the operating modeZH, tZL). (The parts are in operating mode if the –R—E–,the MAX481, MAX485, MAX490, MAX491, andDE ihttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682nputs equal a logical 0,1 or 1,1 or 0, 0.) MAX1487, and are typically 100ns (800ns max) for theMAX483 and MAX487–MAX489. ________________________________________________________________________________ ______11 MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 Low-Power, Slew-Rate-LimitedRS-485/RS-422 TransceiversMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 Figure 14. Receiver Propagation Delay Test Circuit Figure 15. MAX481/MAX485/MAX490/MAX491/MAX1487Receiver tPHL Figure 16. MAX481/MAX485/MAX490/MAX491/MAX1487Receiver tPLH PHLFigure 18. MAX483, MAX487–MAX489 Receiver tPLH 文档下载 免费文档下载 http://www.wendangwang.com/ 12______________________________________________________________________________ ________ Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers Line Length vs. Data Rate Figures 21 and 22 show typical network applicationsThe RS-485/RS-422 standard covers line lengthhttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682s up tocircuits. These parts can also be used as line4000 feet. For line lengths greater than 4000 feet, seerepeaters, with cable lengths longer than 4000 feet, asFigure 23. shown in Figure 23. Figures 19 and 20 show the system differential voltageTo minimize reflections, the line should be terminated atfor the parts driving 4000 feet of 26AWG twisted-pairboth ends in its characteristic impedance, and stubwire at 110kHz into 120?loads. lengths off the main line should be kept as short as possi-Typical Applications ble. The slew-rate-limited MAX483 and MAX487–MAX489The MAX481, MAX483, MAX485, MAX487–MAX491, andare more tolerant of imperfect termination. MAX1487 transceivers are designed for bidirectional datacommunications on multipoint bus transmission lines. DI 5V0V 文档下载 免费文档下载 http://www.wendangwang.com/ 1V VY-VZ 0V-1V RO 5V0V 2?s/div Figure 19.http://www.wendangwang.com/doc/fef468fd14224c89cfe93682 MAX481/MAX485/MAX490/MAX491/MAX1487 SystemFigure 20. MAX483, MAX487–MAX489 System DifferentialDifferential Voltage at 110kHz Driving 4000ft of CableVoltage at 110kHz Driving 4000ft of Cable Figure 21. MAX481/MAX483/MAX485/MAX487/MAX1487 Typical Half-Duplex RS-485 Network ________________________________________________________________________________ ______13 MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 Low-Power, Slew-Rate-LimitedRS-485/RS-422 TransceiversMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 Figure 22. MAX488–MAX491 Full-Duplex RS-485 Network Isolated RS-485 文档下载 免费文档下载 http://www.wendangwang.com/ For isolated RS-485 applications, see the MAX253 andMAX1480 data sheets. Figure 23. Line Repeater for MAX488–MAX491 14______________________________________________________________________________ ________ Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers _______________Ohttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682rdering Information __Ordering Information (continued) * Contact factory for dice specifications. _________________Chip Topographies MAX481/MAX483/MAX485/MAX487/MAX1487 ________________________________________________________________________________ ______15 MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 Low-Power, Slew-Rate-LimitedRS-485/RS-422 TransceiversMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 _____________________________________________Chip Topographies (continued) 文档下载 免费文档下载 http://www.wendangwang.com/ MAX488/MAX490 MAX489/MAX491 SUBSTRATE CONNECTED TO GND 16______________________________________________________________________________ ________ Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package ouhttp://www.wendangwang.com/doc/fef468fd14224c89cfe93682tline informationgo to .) S PE. NCIOS___________________________________________________________________________ ___________17 MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 Low-Power, Slew-Rate-LimitedRS-485/RS-422 TransceiversMAX481/MAX483/MAX485/MAX487–MAX491/MAX1487 文档下载 免费文档下载 http://www.wendangwang.com/ Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline informationgo to .) 18______________________________________________________________________________ ________ Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers 7 Package Information (continued) 8(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information4go to .) 1XS P E.ANPIDPM/194XAM–784XAM/584XAM/384XAM/184XAMMaximhttp://www.wendangwang.com/doc /fef468fd14224c89cfe93682 cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses areimplied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA ____________________19?2003 Maxim Integrated Products 94086 408-737-7600 文档下载 免费文档下载 http://www.wendangwang.com/ Printed USA is a registered trademark of Maxim Integrated Products. MAX481/MAX483/MAX485/MAX487–MAX491 文档下载网是专业的免费文档搜索与下载网站,提供行业资料,考试资料,教 学课件,学术论文,技术资料,研究报告,工作范文,资格考试,word 文档, 专业文献,应用文书,行业论文等文档搜索与文档下载,是您文档写作和查找 参考资料的必备网站。 文档下载 http://www.wendangwang.com/ 亿万文档资料,等你来发现