RS-422

Features:

  ^{_{For Fault-Tolerant Applications
     HWD3430: ±80V Fault-Protected, Fail-Safe, 1/4
     Unit Load, +3.3V, RS-485 Transceiver
     HWD3440EHWD3444E: ±15kV ESD-Protected,
     ±60V Fault-Protected, 10Mbps, Fail-Safe,
     RS-485/J1708 Transceivers
  For Space-Constrained Applications
     HWD3460HWD3464: +5V, Fail-Safe, 20Mbps,
     Profibus RS-485/RS-422 Transceivers
     HWD3362: +3.3V, High-Speed, RS-485/RS-422
     Transceiver in a SOT23 Package
     HWD3280EHWD3284E: ±15kV ESD-Protected,
     52Mbps, +3V to +5.5V, SOT23, RS-485/RS-422,
     True Fail-Safe Receivers
     HWD3293/HWD3294/HWD3295: 20Mbps, +3.3V,
     SOT23, RS-855/RS-422 Transmitters
  For Multiple Transceiver Applications
     HWD3030EHWD3033E:  ±15kV ESD-Protected,
     +3.3V, Quad RS-422 Transmitters
   For Fail-Safe Applications
      HWD3080HWD3089: Fail-Safe, High-Speed
      (10Mbps), Slew-Rate-Limited RS-485/RS-422
      Transceivers
   For Low-Voltage Applications
      HWD3483E/HWD3485E/HWD3486E/HWD3488E/
      HWD3490E/HWD3491E: +3.3V Powered, ±15kV
      ESD-Protected, 12Mbps, Slew-Rate-Limited,
      True RS-485/RS-422 Transceivers}}


Application

^{_{Low-Power RS-485 Transceivers
Low-Power RS-422 Transceivers
Level Translators
Transceivers for EMI-Sensitive Applications
Industrial-Control Local Area Networks}}


Specifications

^{_{Supply Voltage (VCC) .............................................................12V
Control Input Voltage (RE, DE)...................-0.5V to (VCC + 0.5V)
Driver Input Voltage (DI)............................-0.5V to (VCC + 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 (VCC +0.5V)
Continuous Power Dissipation (TA = +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)................471mW
14-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 Ranges
HWD4_ _C_ _/HWD1487C_ A ............................0°C to +70°C
HWD4_ _E_ _/HWD1487E_ A.......................... -40°C to +85°C
HWD4_ _MJ_/HWD1487MJA ........................  55°C to +125°C
Storage Temperature Range ....................... 65°C to +160°C
Lead Temperature (soldering, 10sec)  .......................+300°C}}


Description

These transceivers RS-422 draw between 120µA and 500µA ofsupply current when unloaded or fully loaded with disabled
drivers. Additionally, the HWD481, HWD483, and HWD487have a low-current shutdown modeinwhichtheyconsumeonly 0.1µA. All parts operate from a single 5V supply.

Drivers RS-422 are short-circuit current limited and are protectedagainst excessive power dissipation by thermal shutdown
circuitry that places the driver outputs into a high-imped-ance state. The receiver RS-422 input has a fail-safefeaturethatguarantees a logic-high output if the input is open circuit.

The HWD487 and HWD1487 feature quarter-unit-loadreceiver input impedance, allowing up to 128 HWD487/HWD1487 transceivers on the bus. Full-duplex communi-cations are obtained using the HWD488HWD491, whilethe HWD481, HWD483, HWD485, HWD487, and HWD1487are designed for half-duplex applications.