LTC491CS#TR

The LTC491CS#TR is a low power differential bus transceiver by LT, suitable for multipoint data transmission standards like RS485 and RS422. It features a wide common mode range from -7V to 12V, allowing for up to ±7V ground difference between devices on the bus.

Designed with a CMOS process, this transceiver offers significant power savings compared to bipolar counterparts while maintaining ruggedness against overload and ESD damage. The driver and receiver have three-state outputs, and the driver outputs remain in a high impedance state over the entire common mode range. For protection against excessive power dissipation, a thermal shutdown circuit is integrated, forcing driver outputs into a high impedance state during fault conditions.

Key electrical specifications include a typical quiescent current of 300µA, a single 5V supply requirement, and guaranteed AC/DC specifications from 0°C to 70°C. The receiver includes a fail-safe feature that ensures a high output state when inputs are open. Driver propagation delays are typically 28ns with 5ns skew for 2.5MB operation. The LTC491CS#TR is pin-compatible with the SN75180 and is available in a 14-lead SOIC package suitable for surface mounting.

This transceiver is ideal for low power RS485/RS422 applications and level translation. Its design supports live insertion or removal of packages due to its power-up/down glitch-free driver outputs. The combined impedance of the driver output and receiver allows for up to 32 transceivers on the bus.