LTC2872 - RS232/RS485 Dual Multiprotocol Transceiver with Integrated Termination

The LTC®2872 is a robust pin-configurable transceiver that supports RS232, RS485, and RS422 standards while operating on a single 3V to 5.5V supply. The LTC2872 can be configured as four RS232 single-ended transceivers or two RS485 differential transceivers, or combinations of both, on shared I/O lines.

Pin-controlled integrated termination resistors allow for easy interface reconfiguration, eliminating external resistors and control relays. Half-duplex switches allow four-wire and two-wire RS485 configurations. Loopback mode steers the driver inputs to the receiver outputs for diagnostic self-test. The RS485 receivers support up to 256 nodes per bus, and feature full failsafe operation for floating, shorted or terminated inputs.

An integrated DC/DC boost converter uses a small inductor and one capacitor, eliminating the need for multiple supplies for driving RS232 levels.

Features

Four RS232 and Two RS485 Transceivers
3V to 5.5V Supply Voltage
20Mbps RS485 and 500kbps RS232
Automatic Selection of Integrated RS485 (120Ω) and RS232 (5kΩ) Termination Resistors
Half-/Full-Duplex RS485 Switching
Logic Loopback Mode
High ESD: ±16kV on Line I/O
1.7V to 5.5V Logic Interface
Supports Up to 256 RS485 Nodes
RS485 Receiver Full Failsafe Eliminates UART Lockup
Available in 38-Pin 5mm × 7mm QFN Package