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LTM2881 - Complete Isolated
RS485/RS422 μModule® Transceiver


Linear Technology and Digi-Key introduce the LTM2881 - Complete Isolated RS485/RS422 μModule® Transceiver


Linear Technology LTM2881 μModule Transceiver Linear Technology's 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 5V output DC/DC converter.

Coupled inductors and an isolation power transformer provide 2500V⊂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 30kV/μs.

Maximum data rates are 20Mbps or 250kbps 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 1.62V 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.

Features
  • Isolator μModule technology
  • Isolated RS485/RS422 transceiver: 2500V⊂RMS
  • Integrated isolated DC/DC converter
  • No external components required
  • 20Mbps or low EMI 250kbps data rate
  • High ESD: ±15kV HBM on transceiver interface
  • High common mode transient immunity: 30kV/μs
  • Integrated selectable 120Ω termination
  • 3.3V (LTM2881-3) or 5.0V (LTM2881-5) operation
  • 1.62V to 5.5V logic supply pin for flexible digital interface
  • Common mode working voltage: 560V⊂PEAK
  • High input impedance failsafe RS485 receiver
  • Current limited drivers and thermal shutdown
  • Compatible with TIA/EIA-485-A specification
  • High impedance output during internal fault condition
  • Low current shutdown mode (< 5μA)
  • General purpose CMOS isolated channel
  • Low profile (15mm × 11.25mm × 2.8mm)
Applications
  • Isolated RS485/RS422 interface
  • Industrial networks
  • Breaking RS485 ground loops
RoHS Compliant

Digi-Key Part Number Linear Technology Part Number Description  
LTM2881CV-3#PBF-ND LTM2881CV-3#PBF Complete Isolated RS485/RS422 μModule Transceiver + Power Datasheet
LTM2881CV-5#PBF-ND LTM2881CV-5#PBF
LTM2881IV-3#PBF-ND LTM2881IV-3#PBF
LTM2881IV-5#PBF-ND LTM2881IV-5#PBF