MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-LimitedRS-485/RS-422 TransceiversTOP VIEWVCC1RO2DI3GND4DR8765ABZY DI35YVCC1VCCMAX488MAX490RtD6ZRRODIP/SO8ABAVCCRO12348ZYGNDDI4GNDNOTE: TYPICAL OPERATING CIRCUIT SHOWN WITH DIP/SO PACKAGE.GNDRO2R7BRtDDIMAX488MAX490765μMAXFigure 2. MAX488/MAX490 Pin Configuration and Typical Operating CircuitTOP VIEWDE41234567DR14VCC13N.C.12A11B10Z98YN.C.NC1, 8, 133RO2DI5VCC149YMAX489MAX491RtZ12ARt11BVCCREN.C.ROREDEDIGNDGNDD10RRORDDIDIP/SO6, 7REGNDGNDDEFigure 3. MAX489/MAX491 Pin Configuration and Typical Operating Circuit__________Applications InformationThe 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 Enable(DE) and Receiver Enable (RE) pins are included on theMAX481, MAX483, MAX485, MAX487, MAX489,MAX491, and MAX1487. When disabled, the driver andreceiver outputs are high impedance.
MAX487/MAX1487:128 Transceivers on the BusThe 48kΩ, 1/4-unit-load receiver input impedance of theMAX487 and MAX1487 allows up to 128 transceiverson a bus, compared to the 1-unit load (12kΩinputimpedance) 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 12kΩReceiver Input impedance.
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MAX481/MAX483/MAX485/MAX487–MAX491/MAX1487Low-Power, Slew-Rate-LimitedRS-485/RS-422 Transceivers_______________________________________________________Switching Waveforms3VDI0VZYVOVDIFF0V-VOVO1/2 VO10%tRtSKEW = | tPLH - tPHL |1.5VtPLHtPHL1.5V1/2 VOY, ZVOLVDIFF = V (Y) - V (Z)90?%tF10%Y, Z0V2.3VtZH(SHDN), tZHtHZtZL(SHDN), tZLtLZVOL + 0.5V3VDE0V1.5V1.5V2.3VOUTPUT NORMALLY LOWOUTPUT NORMALLY HIGHVOH - 0.5VFigure 8. Driver Propagation DelaysFigure 9. Driver Enable and Disable Times (except MAX488 andMAX490)3VRE0VROVOHVOLVID-VID0V1.5VtPHLINPUTOUTPUTtPLH0VRO0VtZH(SHDN), tZHtHZ1.5V1.5VVCCROtZL(SHDN), tZLtLZVOL + 0.5V1.5V1.5V1.5VOUTPUT NORMALLY LOWOUTPUT NORMALLY HIGHA-BVOH - 0.5VFigure 10. Receiver Propagation DelaysFigure 11. Receiver Enable and Disable Times (except MAX488and MAX490)_________________Function Tables (MAX481/MAX483/MAX485/MAX487/MAX1487)Table 1. Transmitting
INPUTSREXX01DE1100DI10XXZ01High-ZHigh-Z*OUTPUTSY10High-ZHigh-Z*RE0001Table 2. ReceivingINPUTSDE0000A-B>+0.2V< -0.2VInputs openXOUTPUTRO101High-Z*X = Don’t careHigh-Z = High impedance*Shutdown mode for MAX481/MAX483/MAX487X = Don’t careHigh-Z = High impedance*Shutdown mode for MAX481/MAX483/MAX48710
MEMORY存储芯片MAX483EEPA+中文规格书 - 图文
