MAX485中文手册

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MAX485接口芯片是Maxim公司的一种RS-485芯片。 MAX485CPAMAX485、MAX487-MAX491以及MAX1487是用于RS-485与RS-422通信的低功耗收发器,每个器件中都具有一个驱动器和一个接收器。MAX483、MAX487、MAX488以及MAX489具有限摆率驱动器,可以减小EMI,并降低由不恰当的终端匹配电缆引起的反射,实现最高250kbps的无差错数据传输。MAX481、MAX485、MAX490、MAX491、MAX1487的驱动器摆率不受限制,可以实现最高2.5Mbps的传输速率。
低功耗、限摆率 月S485/RS-422收发器 DC ELECTRICAL CHARACTERISTICS(continued) (cc=5V±5%,TA=T MIN tO I MAX, unless otherwise noted. )(Notes 1 PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS MAX488/MAX489 DE, DI, RE=OV or Vcc 120250 MAX490/MAX491 DE, DI, RE-OV or Vcc MAX481/MAX485 DE = VO 900 No-Load Supply Current (Note 3 Icc RE=OV or Vcc DE=OV JA MAX1487 DE= VcC RE=0∨oVCC DE=OV 230 400 350 650 MA×483/MAX487, DE=5V LMAX483 MAX487 RE=OV or Vcc 250 Supply Current in Shutdown ISHDN MAX481/483/487, DE=OV, RE Driver Short-Circuit Current OsD1-7V<Vo <12V(Note 4) mA Driver Short-Circuit Current 250 mA Vo= Low lOsD2-7V< Vo <12V(Note 4) Receiver Short-Circuit Current OSR 0∨≤Vo≤∨e mA SWITCHING CHARACTERISTICS--MAX481/MAX485 MAX490/MAX491 MAX1487 (Vcc=5V+5%, TA=TmiN to TMAX, unless otherwise noted. )(Notes 1, 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Driver Input to Output tPLH Figures 6 and 8, RDIFF =5492 ns tPHL CL1= CL2=100pF 10 30 Driver Output Skew to Output tsKEW Figures 6 and 8, RDIFF= 5492, CL1=CL2= 100pF 5 10 nS Figures 6 and 8, MAX481,MA×485,MA×1487 15 40 Driver rise or fall time tR, tF RDIFF=5402 MAX490C/E, MAX491C/E 15 25 CL1= CL2=100pF MAX490M. MAX491M 353 15 40 Driver Enable to Output High tZH Figures 7 and 9, CL=100pF, S2 closed 40 70 ∩s s9N Driver Enable to Output Low Figures 7 and 9, CL= 100pF, S1 closed 40 70 Driver disable Tine from low tLz Figures 7 and 9, CL=15pF, S1 closed 40 70 Driver Disable Time from High tHz Figures 7 and 9, CL=15pF, S2 closed 40 70 ns Figures 6 and 10, MAX481, MAX485, MAX1487 20 90 200 Receiver Input to Output tPLH, tPHI RDIFF=5492 MAX490C,MA×4910E 90 150 CL1=CL2= 100pF MAX490M. MAX491M 20 90 200 tplh -tpHL I Differential Figures 6 and 10, RDIFF= 54Q2 Receiver Skew SKD CL1=cL2=1c° Receiver Enable to Output LOw tzL Figures 5 and 11, CRL= 15pF, S1 closed 20 Receiver Enable to Output high tzi Figures 5 and 11, CRL= 15pF, S2 closed Receiver Disable Time from Low tLz Figures 5 and 11, CRL= 15pF, S1 closed 20 nS Receiver Disable Time from High thz Figures 5 and 11, CRL 15pF, S2 closed 20 50 ∩s Maximum Data Rate 2.5 Mbps Time to shutdown tSHDN MAX481 (Note 5) 50 600 ∩s 州AX 低功耗、限摆率 月S-485/RS-422收发器 SWITCHING CHARACTERISTICS--MAX481/MAX485, MAX490/MAX491, MAX1487(continued) (cc=5V+5%, TA= TMIN to TMAX, unless otherwise noted. )(Notes 1, 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Driver Enable from Shutdown to tZH(SHDN) Figures 7 and 9, CL= 100pF, S2 closed 40 Output High(MA×481) 100 ns Driver Enable from Shutdown to Output LOW( MAX481 tZL(SHDN) Figures 7 and 9, CL= 100pF, S1 closed Receiver Enable from Shutdown Figures 5 and 11, CL= 15pF, S2 closed, to Output High(MAX481) tzH(SHDN)A-B=2V 300 1000 ns Receiver Enable frcm shutdown Figures 5 and 11, CL= 15pF, S1 closed, 令「 o Output LOW(WAx481) t71(SHDN)B-A=2V 1000 ns G SWITCHING CHARACTERISTICS-MAX483, MAX487/MAX488/MAX489 (VcC =5V+5%, TA= TMin to TMAx, unless otherwise noted. )(Notes 1, 2) PARAMETER SYMBOL CONDITIONS MIN TYPMAXUNITS 250 800 2000 Driver Input to Output tPLH Figures 6 and 8, RDIFF =54Q tpHL CL1= CL2=100pF ns 250 800 2000 Figures 6 and 8, RDIFF -54Q2 Driver Output Skew to Output tsKEW CLI=CL2=100pF 100 800 ns Driver Rise or Fall Time tR, tE Figures 6 and 8, RDIFF= 5492 2000 CL1=CL2=1000F Driver Enable to Output High tzH Figures 7 and 9, CL = 100pf, S2 closed 2000 Driver Enable to Output LOW tzL Figures 7 and 9, CL 100pF, S1 closed 250 2000 n Driver Disable Time from Low tLz Figures 7 and 9, CL=15pF,S1 closed 300 3000 ns Driver Disable Time from high Figures 7 and 9, CL= 15pF, S2 closed tPlH Figures 6 and 10, RD FF=542 250 2000 Receiver Input to Output n tPHL CL1=CL2=1000F 2000 tplh-tPhl I Differential [SKD a gures 6 and 10, RD FF=5492, 100 ns Receiver Skew L1=CL2=100F Receiver Enable to Output Low Figures 5 and 11, CRL= 15pF, S1 closed 20 ns Receiver Enable to Output Hig Figures 5 and 11, crl= 15pF, s2 closed ns Receiver Disable Time from LOW Figures 5 and 11, CRL= 15pF, S1 closed Receiver Disable Time from High tHz Figures 5 and 11, CRL= 15pF, S2 closed 20 50 Maximum Data Rate fMAX tPLH, tPHL< 50% of data period 250 kbps Time to shutdown ISHDN MAX483/MAX487(Note 5) 50 200 600 ns Driver enable from shutdown to MAX483/MAX487, Figures 7 and 9 2000 Output High tZH(SHDN) Cl=100pF, S2 closed ns Driver Enable from Shutdown totAL(SHDN) CL- 100pF, S1 closed MAX483/MAX487, Figures 7 and 9 2000 Output LOw S Receiver Enable from Shutdown tZH(SHDN A×483MA×487 Figures5and11 2500 to Output High CL= 15pF, S2 closed Receiver Enable from Shutdown tZL(SHDN) CL=15pF, $1 closed MAX483/MAX487, Figures 5 and 11 2500 ns to Output 州X 低功耗、限摆率 月S-485RS-422收发器 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=+25C Note 3: Supply current specification is valid for loaded transmitters when DE= OV 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 less than 50ns, the parts are guaranteed not to enter shutdown If the inputs are in this state for at least 600ns, the parts are guaranteed to have entered shutdown. See Low-Power Shutdown Mode section 曲型工作特性 ICC=5V, TA=+25C, unless otherwise noted. OUTPUT CURRENT VS OUTPUT CURRENT VS RECEIVER OUTPUT HIGH VOLTAGE VS RECEIVER OUTPUT LOW VOLTAGE RECEIVER OUTPUT HIGH VOLTAGE TEMPERATURE 4.4 2cco ∈42 s40 10 433 3.4 2 3.0 0.51.01.52.02.5 152.0253.03.54.0455.0 50-250255075100125 OUTPUT LOW VOLTAGE (V OUTPUT HIGH VOLTAGE (V TEMPERATURE (C) REGEIVER OUTPUT LOW VOLTAGE VS DRIVER OUTPUT CURRENT VS DRIVER DIFFERENTIAL OUTPUT VOLTAGE TEMPERATURE DIFFERENTIAL OUTPUT VOLTAGE VS. TEMPERATURE 09 2.4 R0=8mA-3 80 2.3 R=54g 2.2 s0.5 0.4 35.50 a2.0 SA的NAoSSXA的 219 03 1.8 0.1 10 1.6 1.5 50250255075100125 00.51.0152.02.53.03.54.04.5 -50-250255075100125 TEMPERATURE(°C DIFFERENTIAL OUTPUT VOLTAGE (V) TEMPERATURE(°C) 州AX 5 低功耗、限摆率 月S-485/RS-422收发器 曲型工作特性(续) CC=5V, TA=+25C, unless otherwise noted. OUTPUT CURRENT VS OUTPUT CURRENT VS MAX481/MAX485/MAX490/MAX491 DRIVER OUTPUT LOW VOLTAGE DRIVER OUTPUT HIGH VOLTA SUPPLY CURRENT VS, TEMPERATURE 140 600 MAX481/MAX485 DE=Vcc, RE=X 100 500 100 400 60 乙∝55 -60 300 MAX485: DE=0. RE=X a200 MAX481: DE= RE=O MAX490/MAX491: DE= RE 100 MAX481; DE=0, RE=Vcc 0 0 0 68 1012 7-6-5-4-3-2-1012345 50-250255075100125 OUTPUT LOW VOLTAGE (V) IGH VOLTAGE(V AX483/MAX487-MAX489 MAX1487 SUPPLY CURRENT VS, TEMPERATURE SUPPLY CURRENT VS TEMPERATURE 00 400 IAX483; DE=VcC, RE X1487: DE= Vcn RE=X 300 3 00 200 MAX1487, DE =0V, RE: MAX488/MAX489 DE= RE=X MAX483/MAX437; DE=0, RE= Vcc 50-250255075100125 -60-40-20020406080100120140 TEMPERATURE (C 低功耗、限摆率 月S-485RS-422收发器 引脚说明 引脚 MAX481/MAX483 MAX488/ MAX489/ MAX485/MAX487 MAX490 MAX491 名称 功能 MAX1487 DIP/SO HMAX DIP/SOHMAXDIP/SO 接收器输出:若A>B200mV,则RO为高电平 若A<B200mV,则RO为低电平。 RE 接收器输出使能。当RE为低电平时,RO有效; 当RE为高电平时,RO为高阻状态。 驱动器输岀使能。DE变为高电平时,驱动器输出Y与z有效; DE 当DE为低电平时,驱动器输出为高阻状态。 当驱动器输出有效时,器件被用作线驱动器。而高阻状态卜, 若RE为低电平,则器件被用作线接收器。 驱动器输入。DI上的低电平强制输出Y为低电平,而输出Z为高电平。 同理,D上的高电平强制输出Y为高电平,而输出Z为低电平。 6, GND地 驱动器同相输出端 驱动器反相输出端 A 接收器同相输入端和驱动器同相输出端 12 A 接收器同相输入端 7 B 接收器反相输入端和驱动器反相输出端 B 接收器反相输入端 8 2 14 Ve 正电源:4.75V≤VCC≤5.25V 1,8,13NC.未连接—内部未连接 TOP VIEW AAXA MAX481 MAX483 MAX485 MAX487 MAX1487 L5」GND RO 8VO B DIP/SO DE 3 A W/XI/A8/A 5 GND CC MAX481 GND M4x483 M4X485 M4x48 DE MAX 487 NOTE: PIN LABELS Y AND Z ON TIMING, TEST AND WAVEFORM DIAGRAMS REFER TO PINS A AND B WHEN DE IS HIGH UMAX TYPICAL CPERATING CIRCUIT SHOWN WITH DIP/SO PACKAGE 图1.MAX48AX483/MAX485/MAX487MAX/487引脚配置与典型工作电路 州AX 低功耗、限摆率 月S-485/RS-422收发器 TOP VIEW 巩AX A MA488 A4490 GND 4 D> Y D D 6Z DIP/SO B RO ∠AXW 7 L A2 MAX488 MAX490 6 GND GND GND UMAX NOTE: TYPICAl OPFRATING CIRCUIT SHOWN WITH DIP/SO PACKAGF 图2.MAX48MAX490引脚配置与典型工作电路 TOP VIEW XIA Vcc Re MAX489 N, C 9 Y 13N.C D RE3 12A R Rt D GND B GND 8N.C NC1813 6,7 DIP/SO RE GND GND DE 图3.MAX489MAX491引脚配置与典型工作电路 应用说明 MAX487/MAX 1487 MAX481/MAX483/MAX485/MAX487MAX491以及 总线上可以接128个收发器 MAⅹ1487是用丁RS485与RS422通信的低功耗收发器。与标准RS-485驱动器(最多32个收发器)的单位负载 MAⅹ481、MAⅹ485、MAⅩ490、MAX491以及MA1487(12k输入阻抗)相比,MAX487与MAX1487具有48kg 能够以最高2.5Mbps的数据速率发送并接收数据;而输人电阻,14单位负载的接收器输入阻抗,在一条总线 MAⅹ483、MAⅹ487、MAX488以及MAX489则用于最高上允许最多挂接128个收发器。MAX487MAX1487与其他 250kbps的数据速率。MAX488MAX491是全双工收发 RS-485收发器的任意组合可以允许32个收发器或更少的 器,MAX481、MAX483、MAX485、MAⅹ487以及 收发器连接在同一条总线上。MAX481/MAX83/MAX485 MAX1487是半双工收发器。另外,MAX481、MAX483、与MAX488MAX491具有标准的12kg2接收器输入阻抗。 MAX485、MAX487、MAX489、MAX491以及MAX1487 中包含驱动器使能(DE)与接收器使能(RE)控制引脚, 被禁用时,驱动器或接收器输出为高阻态 州X 低功耗、限摆率 月S-485RS-422收发器 测试电路 RECEIVER TESTPOINT OUTPUT S1 15pF 图4.驱动器直流测试负载 图5.接收器时序测试负载 500g A OUTPUT RD UNDER TEST PL2 图6.驱动器接收器时序测试电路 图7.驱动器时序测试负载 MA×483MAX487MAx488MAx489:图13给出了MAX483、MAX487、MAX488或MAX489在 降低EM和反射相同条件下发送数据时的测试结果。图13中的高频谐波 MAX483以及MAⅹ487-MAX489具有摆率限制,可以减 幅值要低得多,因此,从根本上抑制了EMI 小EMI,并降低由不恰当的终端匹配电缆引起的反射。 图12给出了驱动器输出波形以及使用MAX481 MAX485、MAⅹ490、MAX491或MAX1487发送150kH 信号时的傅立叶分析。有明显的大幅值高频谐波 州AX 9 低功耗、限摆率 月S-485/RS-422收发器 开关波形 D 1.5V 15V DE 1.5V 1 2 Vo tzL 2.3V OUTPUT NORMALLY LOW V0L+0.5V 1/2 Vo VDIFF=V(Y)-V(Z) OUTPUT NORMALLY HIGH YZ 9C% g0% 23V VOH -05V t R tF ZH(SHDN),ZH tsKEW= I tpLH-tPHL I 图8.驱动器传输延时 图9.驱动器使能与禁用时序MAK488与MAX490例外) RE 15V OH VOL 1.5V L(SHDN OUTPUT tpHL tpLH 1.5V OUTPUT NORMALLY LOW VoL +0.5v A-B INPUT OUTPUT NORMALLY HIGH 15 VOH-0.5V tzH(SHDN), tZH 图10.接收器传输延时 图1.接收器使能与禁用时序MAX488与MAX490例外 功能表(MAX481MMAX483MAX485/AX487MAX1487) 文表1发送 表2.接收 INPUTS OUTPUTS INPUTS OUTPUT DE Y RE DE A-B RO 0 High-Z High -Z 0 Inputs op 0 High-Z* High-Z High-Z X= Don't care X= Don't care High-Z= High impedance High-Z= High impedance x Shutdown mode for MAX481/MAX483/MAX487 Shutdown mode for max481/MA×483/MA×487 10 州X

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试读 19P MAX485中文手册
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m0_37375675 很有用,多谢分享
2017-10-02
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whyliao 对于MAX485芯片的应用有帮助
2014-08-30
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l240091133 手册里还是英文的,诶,有点失望
2014-03-29
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古蛇拜阳 手册是好东西,对我们学习485芯片很有帮助。
2013-12-03
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