Ultra low power differential line transceiver

The LTC1487 is an ultra-low power differential line transceiver designed with a high impedance input that allows up to 256 transceivers to share a single bus. Fully specified in commercial temperature ranges and available in 8-pin DIP and SO packages. Meet the requirements for RS485 and RS422. The LTC1487's output driver has a controlled conversion rate that reduces EMI radiated from the RS485 line and improves signal fidelity with the mistterminated line.

CMOS designs offer significant power savings without sacrificing robustness against overload or ESD damage. The typical static current is only 80 μA when working and 1 μA when down. The driver and receiver have three-state outputs, and the driver output maintains a high impedance throughout the common model perimeter.

Excessive power consumption due to bus contention or failure is prevented by a thermal shutdown circuit that forces the driver output into a high impedance state. The receiver has a fail-safe feature that guarantees a high output state when the input is turned on. Use a mannequin to protect the I/O pins from multiple ESD strikes over ±10kV.

Features

● High Input Impedance: Up to 256 Transceivers on the Bus
● Low Power: ICC = 120µA Max with Driver Disabled
● ICC = 200µA Max with Driver Enabled, No Load
● 1µA Quiescent Current in Shutdown Mode
● Controlled Slew Rate Driver for Reduced EMI
● Single 5V Supply
● ESD Protection to ±10kV On Receiver Inputs and inputs driver outputs
● -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
● Pin Compatible with the LTC485

Applications

● Battery powered RS485/RS422 applications
● Low power RS485/RS422 transceiver
● Level converter