Features

• Integrated, Logic-Selectable 120Ω Termination Resistor
• 3.3V Supply Voltage
• 20Mbps Maximum Data Rate
• No Damage or Latchup Up to ±25kV HBM
• High Input Impedance Supports 256 Nodes (C-, I‑Grade)
• Operation Up to 125°C (H-Grade)
• Guaranteed Failsafe Receiver Operation Over the Entire Common Mode Range
• Current Limited Drivers and Thermal Shutdown
• Delayed Micropower Shutdown: 5μA Maximum (C-, I-Grade)
• Power Up/Down Glitch-Free Driver Outputs
• Low Operating Current: 370μA Typical in Receive Mode
• Compatible with TIA/EIA-485-A Specifications
• Available in 10-Pin 3mm × 3mm DFN, 12-Pin 4mm × 3mm DFN and 16-Pin SSOP Packages

Typical Application

Description

The LTC®2854 and LTC2855 are low power, 20Mbps RS485/RS422 transceivers operating on 3.3V supplies. The receiver includes a logic-selectable 120Ω termination, one-eighth unit load supporting up to 256 nodes per bus (C-, I-Grade), and a failsafe feature that guarantees a high output state under conditions of floating or shorted inputs.

The driver maintains a high output impedance over the entire common mode range when disabled or when the supply is removed. Excessive power dissipation caused by bus contention or a fault is prevented by current limiting all outputs and by a thermal shutdown.

Enhanced ESD protection allows the LTC2854 to withstand ±25kV (human body model) and the LTC2855 to withstand ±15kV on the transceiver interface pins without latchup or damage.