GENERAL DESCRIPTION

The ADM3493 is a low power, differential line transceiver designed to operate using a single 3.3 V power supply. Low power consumption, coupled with a shutdown mode, makes it ideal for power-sensitive applications. The ADM3493 is suitable for communication on multipoint bus transmission lines.

The device contains one driver and one receiver. Designed for half-duplex communication, the ADM3493 features a slew rate limited driver that minimizes EMI and reduces reflections caused by improperly terminated cables, allowing error-free data transmission at data rates up to 250 kbps.

The receiver input impedance is 96 kΩ, allowing up to 256 transceivers to be connected on the bus. A thermal shutdown circuit prevents excessive power dissipation caused by bus contention or by output shorting. If a significant temperature increase is detected in the internal driver circuitry during fault conditions then the thermal shutdown circuit forces the driver output into a high impedance state. The receiver contains a fail safe feature that results in a logic high output state, if the inputs are unconnected (floating).

The ADM3493 is fully specified over the commercial and industrial temperature ranges and is available in an 8-lead SOIC.

FEATURES

Operates with 3.3 V supply

Interoperable with 5 V logic

EIA RS-422 and RS-485 compliant over full CM range

Data rate: 250 kbps

Half duplex transceiver

Reduced slew rates for low EMI

2 nA supply current in shutdown mode

Up to 256 transceivers on a bus

−7 V to +12 V bus common-mode range

Specified over −40°C to +85°C temperature range

8 ns skew

Available in 8-lead SOIC

APPLICATIONS

Low power RS-485 applications

EMI sensitive systems

DTE-DCE interfaces

Industrial control

Packet switching

Local area networks

Level translators