ADM2481BRWZ Integrated Circuit Chip RS-485 Transceiver with 2.5KV Signal Isolation 500Kbps Half Duplex and 3-Channel Isolator

The ADM2481 differential bus transceiver is an integrated, galvanically isolated component designed for bidirectional data communication on balanced, multipoint bus transmission lines. It complies with ANSI EIA/TIA-485-A and ISO 8482:1987(E) standards. Utilizing iCoupler® technology, the ADM2481 combines a 3-channel isolator, a three-state differential line driver, and a differential input receiver into a single package. The logic side operates with either 5V or 3V supply, while the bus side uses a 5V supply exclusively.

The device features slew-limited outputs to minimize reflections with improperly terminated transmission lines, with a controlled slew rate limiting data transmission to 500 kbps. With an input impedance of 96 kΩ, the ADM2481 supports up to 256 transceivers on the bus. The driver includes an active-high enable feature, and both driver differential outputs and receiver differential inputs are internally connected to form a differential I/O port. When disabled or when power supplies are at 0V, the device imposes minimal loading on the bus. An active-high receiver disable feature is also provided.