3.3 V, ±15 kV ESD-Protected, RS-485/RS-422 Transceiver (Half Duplex, 250kbps, DE/RE)

The ADM3483E / ADM3486E / ADM3488E / ADM3490E / ADM3491E are 3.3 V, low power data transceivers with ±15 kV ESD protection suitable for full- and half-duplex communication on multipoint bus transmission lines. They are designed for balanced data transmission, and they comply with TIA/EIA standards RS485 and RS-422. The ADM3483E / ADM3486E are half-duplex transceivers that share differential lines and have separate enable inputs for the driver and receiver. The full-duplex ADM3488E / ADM3490E / ADM3491E transceivers have dedicated differential line driver outputs and receiver inputs. The ADM3491E also features separate enable inputs for the driver and receiver.

The devices have a 12 kΩ receiver input impedance, which allows up to 32 transceivers on a bus. Because only one driver should be enabled at any time, the output of a disabled or powered-down driver is tristated to avoid overloading the bus.

The driver outputs of the ADM3483E / ADM3486E / ADM3488E are slew rate limited, in order to reduce EMI and data errors caused by reflections from improperly terminated buses. The receiver has a fail-safe feature that ensures a logic high output when the inputs are floating. Excessive power dissipation caused by bus contention or by output shorting is prevented with a thermal shutdown circuit. The parts are fully specified over the industrial temperature range and are available in 8-lead and 14-lead narrow SOIC packages.

APPLICATIONS

* Power/energy metering

* Telecommunications

* EMI-sensitive systems

* Industrial control

* Local area networks

* TIA/EIA RS-485/RS-422 compliant

* ±15 kV ESD protection on RS-485 input/output pins

* Data rates: ADM3483E/ADM3488E: 250 kbps

* Half duplex options

* Up to 32 nodes on the bus

* Receiver open-circuit, fail-safe design