Features

• RS485/RS422 Transceiver: 6500V_RMS for 1 Minute
• Reinforced Insulation
• Isolated DC Power: 5V at 150mA
• No External Components Required
• 20Mbps or Low EMI 250kbps Data Rate
• High ESD: ±15kV HBM on Transceiver Interface
• High Common Mode Transient Immunity: 50kV/μs
• Integrated Selectable 120Ω Termination
• Extended Creepage and Clearance ~14.6mm
• 1.62V to 5.5V Logic Supply Pin for Flexible Digital Interface
• Maximum Continuous Working Voltage: 690V_RMS
• High Input Impedance Failsafe RS485 Receiver
• Current Limited Drivers and Thermal Shutdown
• Compatible with TIA/EIA-485-A and PROFIBUS
• High Impedance Output During Internal Fault Condition
• Low Current Shutdown Mode (< 10μA)
• General Purpose CMOS Isolated Channel
• 22mm × 9mm × 5.16mm Surface Mount BGA Package

Typical Application

Description

The LTM®2885 is a complete galvanically isolated full-duplex RS485/RS422 μModule® (micromodule) 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.

Coupled inductors and an isolation power transformer provide 6500V_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 up to 50kV/μs.

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 ±25kV through the isolation barrier to logic supplies without latch-up or damage.