The ADM1487 is an ultra-low power RS-485/RS-422 transceiver consisting of one driver and one receiver per package. Quiescent operating current is typically 80µA and 1µA in shutdown mode. The driver and receiver both have three-state outputs. This allows multiple drivers to be connected to an RS-485/RS-422 bus, or several receiver outputs to be connected to a serial data bus. The driver will maintain a high-impedance output state even with power off, while the receiver features fail-safe operation that guarantees a logic high output if the inputs are left open-circuit. The device has slew-rate limited drivers to minimize electromagnetic interference (EMI) and reduce reflections caused by incorrectly terminated cables.
The ADM1487 is an ultra‑low‑power RS‑485/RS‑422 transceiver featuring a low‑current shutdown mode, high input impedance that allows up to 256 receivers on a bus, and controlled slew‑rate drivers to minimise EMI and signal reflections. It provides ±10 kV ESD protection on the I/O pins and includes thermal and current‑limit protection for fault conditions.
The datasheet lists detailed electrical and switching characteristics, pin configurations, ordering information, typical performance curves, and mechanical dimensions. Key specifications include a maximum data rate of 250 kbps, supply current of up to 200 µA (driver enabled) and 1‑10 µA in shutdown, and a driver common‑mode output voltage of 3 V.
| Maximum Data Rate | 250 kbps |
|---|---|
| Supply Current (Driver Enabled) | 200 µA (max) |
| Supply Current (Shutdown Mode) | 1‑10 µA |
| Input High Voltage (DE, DI, RE) | 2 V |
| ESD Protection | ±10 kV (Human Body Model) |
| Maximum Receivers on Bus | 256 |
The device supports a maximum data rate of 250 kbps.
Up to 256 receivers can be connected on the bus.
In shutdown mode the supply current is typically between 1 µA and 10 µA.
The transceiver provides ±10 kV ESD protection on its RS‑485 I/O pins.