Multiprotocol transceiver IC supports legacy peripherals in industrial designs

July 08, 2016 // By Graham Prophet
Exar’s XR34350sSupports broader range of RS-232 peripherals with ±10V RS-232 driver output; reduces component count and saves board space as a result of integrated cable termination; and supports full DB9 RS-232 or RS-485/RS-422 serial protocols.

Joining a family of single-chip RS-232/RS-485/RS-422 serial transceivers, XR34350 features a wide range driver output, integrated cable termination and four configuration modes that allow all three protocols to be used interchangeably over a single cable or connector with no additional switching components. The RS-232 mode provides three drivers and five receivers to support all eight signals required for the DB9 serial port (3TX/5RX), while RS-485/422 modes include both half and full duplex (1TX/1RX).


The XR34350 operates from either a 3.3V or 5V supply, consumes 2 mA typical supply current, and offers a shutdown mode for low power (10 µA) standby operation. The high speed drivers operate up to 20 Mbps in RS-485/422 modes, and up to 1 Mbps in RS-232 mode. All drivers can be slew limited to 250 kbps in any mode to minimize electromagnetic interference (EMI). Exar adds that the

wide driver output swing allows improved interoperability with older model bar code scanners, PS2 keyboards/mice, and other RS-232 peripherals.


All bus pins are protected against severe ESD events up to ±15 kV HBM (Human Body Model), ±15 kV IEC-61000-4-2 Air Gap, and ±8 kV IEC 61000-4-2 Contact Discharge. In 6 x 6 mm, 40-pin QFN package, pricing starts at $5.40 (1,000).