MEMORY存儲(chǔ)芯片ADM487EARZ-REEL7中文規(guī)格書

1、 ADM485E/ADM487E/ADM1487EFEATURESFUNCTIONAL BLOCK DIAGRAMTIA/EIA RS-485/RS-422 compliantESD protection on RS-485 I/O pins15 kV human body model (HBM)Data ratesVCCADM485E/ADM487E/ADM1487EADM487E: 250 kbpsRORERADM485E/ADM1487E: 2.5 MbpsHalf-duplexABReduced slew rates for low EMICommon-mode input range

2、: 7 V to +12 VThermal shutdown and short-circuit protection8-lead SOIC packagesDEDID100ADM487EW qualified for automotive applications5-6GND360Figure 1.APPLICATIONSEnergy/power meteringLighting systemsIndustrial controlTelecommunicationsSecurity systemsInstrumentationGENERAL DESCRIPTIONThe ADM485E/AD

3、M487E/ADM1487E are 5 V, low powerdata transceivers with 15 kV ESD protection suitable for half-duplex communication on multipoint bus transmission lines.They are designed for balanced data transmission and complywith Telecommunication Industry Association/ElectronicsIndustries Association (TIA/EIA)

4、standards RS-485 and RS-422.The ADM487E and ADM1487E have a 1/4 unit load receiverinput impedance that allows up to 128 transceivers on a bus,whereas the ADM485E allows up to 32 transceivers on a bus.Because only one driver is enabled at any time, the output of adisabled or power-down driver is thre

5、e-stated to avoid overloadingthe bus.The driver outputs are slew rate limited to reduce EMI and dataerrors caused by reflections from improperly terminated buses.Excessive power dissipation caused by bus contention or outputshorting is prevented with a thermal shutdown circuit.The parts are fully sp

6、ecified over the industrial temperatureranges and are available in 8-lead SOIC packages.Table 1. Selection TableDuplex(Mbps)LimitedShutdownCurrent (A)NoNoYesNoYes300120230328880.252.5YesYes128128ADHM1487EalfNoYes ADM485E/ADM487E/ADM1487ESPECIFICATIONSV = 5 V 10%, T = T to T , unless otherwise noted.

7、MINCCAMAXTable 2. ADM485E/ADM487E/ADM1487EParameterSymbol5 V2L= 27 (RS-485) (see Figure 18)L= 27 or 50 (see Figure 18)LR = 27 or 50 (see Figure 18)VLVV1.00.25V = 0 V or 5.25 V, V = 7 V(ADM487E/ADM1487E)Differential Input Threshold VoltageInput HysteresismVVIOUT = 4 mA, V = +200 mV0.41VIOUT = +4 mA,

8、V = 200 mVThree-State Output Leakage CurrentReceiver Input ResistanceO7 V V +12 V (ADM485E)CM7 V V +12 V (ADM487E/ADM1487E)RE = 0 V or V , DE = V (ADM485E)RE = 0 V or V , DE = 0 V (ADM485E)CCRE = 0 V or V , DE = V (ADM1487E)RE = 0 V or V , DE = 0 V (ADM1487E)CCRE = 0 V or V , DE = V (ADM487E)10CC7 V

9、 V +12 V, applies to peak current250250O7 V V +12 V, applies to peak currentOReceiver Short-Circuit CurrentOESD PROTECTIONA, B15kVHuman body model1Supply voltage is 5 V 5%.Rev. B | Page of 16 ADM485E/ADM487E/ADM1487ETIMING SPECIFICATIONSV = 5 V 10%, T = T to T , unless otherwise noted.MINCCAMAXTable

10、 3. ADM485E/ADM1487EParameterTest Conditions/Comments= 54 , C = C = 100 pF10 40 6010 40 60RDPLHDPHLSKEWL1L2(see Figure 19 and Figure 20)= 54 , C = C = 100 pFRL1L2(see Figure 19 and Figure 20)R = 54 , C = C = 100 pF5L1L2(see Figure 19 and Figure 20)= 54 , C = C = 100 pF20RL1L2(see Figure 19 and Figur

11、e 20)t45454545nsnsnsnsC = 100 pF, S1 closed (see Figure 21)LtC = 100 pF, S1 closed (see Figure 22)LtC = 15 pF, S1 closed (see Figure 22)LtC = 15 pF, S1 closed (see Figure 21)LtSee Figure 23 and Figure 24See Figure 23 and Figure 24See Figure 23 and Figure 24tt525nsPLHSKEWEnable Time to Low LevelEnabl

12、e Time to High LevelDisable Time from Low LevelDisable Time from High LevelMAXIMUM DATA RATEt50505050nsC = 15 pF, S2 closed (seeFigure 25)Lt20nsC = 15 pF, S1 closed (seeFigure 25)RZHLt20nsC = 15 pF, S2 closed (seeFigure 25)RLZLt , t 50% of data periodt20nsRHZPLH PHLf2.5MbpsMAXRev. B | Page of 16 ADM

13、485E/ADM487E/ADM1487ETYPICAL PERFORMANCE CHARACTERISTICS5045400.90.80.70.60.50.40.30.20.10)V)A(3530252015105EGATLOm(TNERRUCVWOLTUPTTUPTIUOUO610910-6653605360000.51.01.52.02.54020020TEMPERATURE (C)406080OUTPUT LOW VOLTAGE (V)Figure 3. Output Current vs. Receiver Output Low VoltageFigure 6. Receiver Output Low Voltage vs. TemperatureRev. B | Page of 16 ADM485E/ADM487E/ADM1487ETT33AB22BA18201030RO-6653605360CH1 5.00V CH2 500mVCH3 500mVM200nsA CH12.80VCH1 5.00V CH2 500mVCH3 500mVM20nsT 60.80%A CH12.70VT 60.80%Figure 15. ADM487E