ADM3491E 3.3 V, ±15 kV ESD-Protected, RS-485/RS-422 Transceiver (Full Duplex, 12Mbps, DE/RE)

The ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E are 3.3 V low power data transceivers with ±15 kV ESD protection suitable for fulland half-duplex communication on multipoint bus transmission lines. They are designed for balanced data transmission and comply with TIA/EIA standards RS-485 and RS-422. The ADM3483E/ADM3486E is a half-duplex transceiver that shares differential lines and has 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 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. Since only one driver should be enabled at any time, the output of a disabled or powered down driver is three-stated 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 failsafe feature which 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 ranges and are available in narrow 8-lead and 14-lead (ADM3491E) SOIC packages.

Features and Benefits

TIA/EIA RS-485/RS-422 compliant
±15 kV ESD-protection on RS-485 input/output pins
Data rates - ADM3490E/ADM3491E: 12 Mbps
Full duplex
32 nodes on the bus
Receiver open-circuit, fail-safe design

Low power shutdown current (ADM3483E/ADM3486E/ADM3491E only)
Outputs high-Z when disabled or powered off
−7 V to +12 V common-mode input range
Thermal shutdown and short-circuit protection
Industry-standard 75176 pinout
14-lead SOIC package

Interface & Isolation

Interface RS-485 and RS-422

IBIS Models

ADM3491E IBIS Model .IBS

Data Sheets

Document	note
ADM3483E/ADM3486E/ADM3488E/ADM3490E/ADM3491E: 3.3 V, ±15 kV ESD-Protected, Half- and Full-Duplex, RS-485/RS-422 Transceivers Data Sheet (Rev. A)	PDF 643 kB

Application Notes

Document	note
AN-1176: Component Footprints and Symbols in the Binary .Bxl File Format (Rev. 0)	PDF 671 kB
AN-960: RS-485/RS-422 Circuit Implementation Guide (Rev. 0)	PDF 245 kB