The LTC1487 is an ultra-low power differential line transceiver designed with high impedance inputs allowing up to 256 transceivers to share a single bus. It meets the requirements of RS485 and RS422. The LTC1487 features output drivers with controlled slew rate, decreasing the EMI radiated from the RS485 lines, and improving signal fidelity with misterminated lines. The CMOS design offers significant power savings without sacrificing ruggedness against overload or ESD damage. Typical quiescent cur- rent is only 80µA 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. I/O pins are protected against multiple ESD strikes of over ±10kV using the Human Body Model. The LTC1487 is fully specified over the commercial tem- perature range and is available in 8-pin DIP and SO packages.
The LTC1487 is a CMOS differential line transceiver designed for RS485 and RS422 applications. It features ultra‑low power consumption, high input impedance (up to 256 transceivers on a single bus), controlled slew‑rate drivers for reduced EMI, and built‑in thermal shutdown and ESD protection.
The device is supplied in 8‑pin DIP and SO packages and includes detailed electrical characteristics, pin functions, switching times, and typical performance data such as quiescent current, maximum data rate, and input impedance. It supports both driver and receiver three‑state operation and can enter a shutdown mode with sub‑microampere current draw.
| Quiescent Current (Shutdown Mode) | ≈ 1 pA |
|---|---|
| Maximum Data Rate | 250 kbps |
| Thermal Shutdown Temperature | 150 °C (turn‑off), 130 °C (turn‑on) |
The device draws about 1 pA of supply current in shutdown mode.
The LTC1487 supports a maximum data rate of 250 kbps.