Features

• No Damage or Latchup to ±15kV (Human Body
  Model), IEC1000-4-2 Level 4 (±8kV) Contact and
  Level 3 (±8kV)
• Active Low Carrier Detect Output
• Guaranteed High Receiver Output State for
  Floating, Shorted or Terminated Inputs with
  No Signal Present
• Drives Low Cost Residential Telephone Wires
• Low Power: I_CC = 700µA Max with Driver Disabled
• I_CC = 900µA Max in Driver Mode Without Load
• 20µA Max Quiescent Current in Shutdown Mode
• Single 5V Supply
• –7V to 12V Common Mode Range Permits ±7V
  Ground Difference Between Devices on the Data Line
• Maximum Data Rate of 4Mbps
• Power Up/Down Glitch-Free Driver Outputs
• Up to 32 Transceivers on the Bus
• Available in 8-Lead MSOP, PDIP and SO Packages

Typical Application

Description

The LTC®1482 is a low power RS485 compatible transceiver that offers an active low carrier detect output. The open-drain carrier detect pin allows several transceivers to share the same carrier detect line and can be used to detect the insertion or removal of a driven RS485/RS422 cable. Enhanced ESD protection allows the LTC1482 to withstand ±15kV (human body model), IEC-1000-4-2 level 4 (±8kV) contact and level 3 (±8kV) air discharge ESD without latchup or damage. The LTC1482 receiver stays alive at all times except in shutdown. The supply current is a maximum of 700µA and 900µA when the driver is disabled and enabled respectively. In shutdown, the quiescent current of the LTC1482 drops to a maximum of 20µA. When the driver is disabled or the LTC1482 is in shutdown, the driver outputs are three-stated and remain in a high impedance state over the RS485 common mode range. 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 LTC1482 is fully specified over the commercial and industrial temperature ranges and is available in 8-lead MSOP, PDIP and SO packages.