Description

The ADM485ARZ is a differential line transceiver designed for balanced data transmission and is compliant with the EIA standards RS-485 and RS-422. It contains a differential line driver and a differential line receiver that can be enabled independently, and both can be disabled resulting in three-stated outputs. This device features a thermal shutdown circuit that prevents excessive power dissipation caused by bus contention or output shorting. Its maximum bus common-mode range is -7 V to +12 V. Additionally, the receiver incorporates a fail-safe feature that results in a logic high output state when the inputs are not connected.

Specifications and features

• Max. data rate of 5 Mbps
• Single 5 V power supply
• Short-circuit protection
• High-speed, low-power BiCMOS technology
• Driver propagation delay: 10 ns typical
• Receiver propagation delay: 15 ns typical
• 8-lead PDIP, 8-lead SOIC, and 8-lead MSOP packages

Application Scenarios

The ADM485ARZ is ideal for use in low-power RS-485 systems, data concentration, data multiplexers, packet switching, and integrated services digital networks (ISDN).

Comparison

• Complies with both EIA standards RS-485 and RS-422
• Contains a fail-safe feature in the receiver
• Thermal shutdown circuit for excessive power dissipation protection
• Up to 32 transceivers can be connected simultaneously

• Only one driver should be enabled at any time
• One disabled driver should not load the bus, but this is helped by the ADM485 having a high impedance driver output when disabled and powered down