ADM2483

The ADM2483 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). Using Analog Devices' iCoupler technology, the ADM2483 combines a 3-channel isolator, a three-state differential line driver, and a differential input receiver into a single package. The logic side of ADM2483  is powered with either a 5 V or 3 V supply, and the bus side uses a 5 V supply only.

The ADM2483 is slew-limited to reduce reflections with improperly terminated transmission lines. The controlled slew rate limits the data rate to 500 kbps. The device's input impedance is 96 kΩ, allowing up to 256 transceivers on the bus. Its driver has an active-high enable feature. The driver differential outputs and receiver differential inputs are connected internally to form a differential I/O port. When the driver is disabled or when V_DD1 or V_DD2 = 0 V, this imposes minimal loading on the bus. An active-high receiver disable feature, which causes the receive output to enter a high impedance state, is provided as well.

The ADM2483 receiver inputs have a true fail-safe feature that ensures a logic-high receiver output level when the inputs are open or shorted. This guarantees that the receiver outputs are in a known state before communication begins and at the point when communication ends.

Current limiting and thermal shutdown features of ADM2483 protect against output short circuits and bus contention situations that might cause excessive power dissipation. The part is fully specified over the industrial temperature range and is available in a 16-lead, wide body SOIC package.