LTM2881 - Complete Isolated RS485/RS422 μModule® Transceiver

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

Image of Linear Technology's LTM2881 - Complete Isolated RS485/RS422 μModule® TransceiverLinear 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 5 V output DC/DC converter.

Coupled inductors and an isolation power transformer provide 2500 VRMS 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.

  • Isolator μModule technology
  • Isolated RS485/RS422 transceiver: 2500 VRMS
  • Integrated isolated DC/DC converter
  • No external components required
  • 20 Mbps or low EMI 250 kbps data rate
  • High ESD: ±15 kV HBM on transceiver interface
  • High common mode transient immunity: 30 kV/μs
  • Integrated selectable 120 Ω termination
  • 3.3 V (LTM2881-3) or 5.0 V (LTM2881-5) operation
  • 1.62 V to 5.5 V logic supply pin for flexible digital interface
  • Common mode working voltage: 560 VPEAK
  • 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 (< 5 μA)
  • General purpose CMOS isolated channel
  • Low profile (15 mm x 11.25 mm x 2.8 mm)


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


ImageManufacturer Part NumberDescriptionAvailable Quantity
LTM2881IV-5#PBF datasheet linkDGTL ISO 2.5KV RS422/RS485 32LGALTM2881IV-5#PBFDGTL ISO 2.5KV RS422/RS485 32LGA1965 - Immediate
LTM2881IV-5#PBF product page link
LTM2881IV-3#PBF datasheet linkDGTL ISO 2.5KV RS422/RS485 32LGALTM2881IV-3#PBFDGTL ISO 2.5KV RS422/RS485 32LGA1098 - Immediate
LTM2881IV-3#PBF product page link
LTM2881CV-5#PBF datasheet linkDGTL ISO 2.5KV RS422/RS485 32LGALTM2881CV-5#PBFDGTL ISO 2.5KV RS422/RS485 32LGA604 - Immediate
LTM2881CV-5#PBF product page link
LTM2881CV-3#PBF datasheet linkDGTL ISO 2.5KV RS422/RS485 32LGALTM2881CV-3#PBFDGTL ISO 2.5KV RS422/RS485 32LGA339 - Immediate
LTM2881CV-3#PBF product page link
Published: 2012-06-29