Features

• No Damage or Latchup to ±15kV ESD (Human Body
  Model), IEC1000-4-2 Level 4 (±8kV) Contact and Level 3 (±8kV)
• Guaranteed High Receiver Output State for
  Floating, Shorted or Terminated Inputs with No
  Signal Present
• Drives Low Cost Residential Telephone Wires
• I_CC = 600µA Max with No Load
• Single 5V Supply
• –7V to 12V Common Mode Range Permits ±7V
  Ground Difference Between Devices on the Data Line
• Power-Up/Down Glitch-Free Driver Outputs Permit
  Live Insertion or Removal of Transceiver
• Driver Maintains High Impedance with the Power Off
• Up to 32 Transceivers on the Bus
• Pin Compatible with the SN75179 and LTC490
• Available in SO, MSOP and PDIP Packages

Typical Application

Description

The LTC®1690 is a low power receiver/driver pair that is compatible with the requirements of RS485 and RS422. The receiver offers a fail-safe feature that guarantees a high receiver output state when the inputs are left open, shorted together or terminated with no signal present. No external components are required to ensure the high receiver output state. Separate driver output and receiver input pins allow full duplex operation. Excessive power dissipation caused by bus contention or faults is prevented by a thermal shutdown circuit which forces the driver outputs into a high impedance state. The LTC1690 is fully specified over the commercial and industrial temperature ranges. The LTC1690 is available in 8-Pin SO, MSOP and PDIP packages.