Linear Technology: DC1746A Demo Board for LTM2881 Isolated RS485/RS422 μModule Transceiver + Power

Kit Overview

Demonstration circuit DC1746ADC1746A is an isolated RS485/RS422 μModule transceiver + power featuring the LTM2881LTM2881. The demo circuit is a 2500VRMS galvanically isolated RS485/RS422 transceiver interface. The demo circuit features an EMI optimized circuit confi guration and printed circuit board layout. All components are integrated into the μModule transceiver. The demo circuit operates from a single external supply on VCC. The part generates the output voltage VCC2 and communicates all necessary signaling across the isolation barrier using LTC’s isolator μModule technology.

The LTM2881LTM2881 is a complete galvanically isolated fullduplex 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 5V output DC/DC converter.

Maximum data rates are 20Mbps or 250kbps in slew limited mode. Transmit data, DI and receive data, RO, are 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 1.62V to 5.5V, independent of the main supply.

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

Ordering Information:

Key Applications: Isolated RS485/RS422 Interface, Industrial Networks, Breaking RS485 Ground Loops, Isolated PROFIBUS-DP Networks