LTM2881 - Complete Isolated RS485/RS422 μModule® Transceiver

Analog Devices' LTM2881 is a complete galvanically isolated full-duplex RS485/RS422 μModule transceiver. No external components are required. A single supply powers both sides of the interface through an integrated, isolated, low noise, efficient 5 V output DC/DC converter.

Coupled inductors and an isolation power transformer provide 2500 V_RMS of isolation between the line transceiver and the logic interface. This device is ideal for systems where the ground loop is broken allowing for large common mode voltage variation. Uninterrupted communication is guaranteed for common mode transients greater than 30 kV/μs.

Maximum data rates are 20 Mbps or 250 kbps in slew limited mode. Transmit data, DI and receive data, RO, implemented with event driven low jitter processing. The receiver has a one-eighth unit load supporting up to 256 nodes per bus. A logic supply pin allows easy interfacing with different logic levels from 1.62 V to 5.5 V, independent of the main supply.

Enhanced ESD protection allows this part to withstand up to ±15 kV (human body model) on the transceiver interface pins to isolated supplies and ±10 kV through the isolation barrier to logic supplies without latch-up or damage.

Applications

• Isolated RS485 / RS422 interface
• Industrial networks
• Breaking RS485 ground loops