Features

• True RS485 from a Single 3.3V Supply
• Low Power: I_CC = 500µA Max with Driver Disabled
• I_CC = 600µA Max with Driver Enabled, No Load
• 1µA Quiescent in Shutdown Mode
• -7V to 12V Common Mode Range Permits ±7V Ground Difference Between Devices on the Data Line
• Thermal Shutdown Protection
• Power Up/Down Glitch-Free Driver Outputs Permit Live Insertion or Removal of Transceiver
• Driver Maintains High Impedance in Three-State or with the Power Off
• Up to 32 Transceivers on the Bus
• 50ns Typical Driver Propagation Delays with 10ns Skew
• Pin Compatible with the LTC485
• Available in 8-Lead DIP and SO Packages

Typical Application

Description

The LTC®1480 is an ultralow power differential line transceiver which provides full RS485 compatibility while operating from a single 3.3V supply. It is designed for data transmission standard RS485 applications with extended common mode range (12V to -7V). It also meets the requirements of RS422 and features high speed operation up to 2.5Mb/s. The CMOS design offers significant power savings without sacrificing ruggedness against overload or ESD damage. Typical quiescent current is only 300µA while operating and 1µA in shutdown.

The driver and receiver feature three-state outputs, with the driver outputs maintaining high impedance over the entire 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 receiver has a fail-safe feature which guarantees a high output state when the inputs are left open.

The LTC1480 is fully specified over the commercial and extended industrial temperature range. The LTC1480 is available in 8-pin SO and DIP packages.