The SP332 is a monolithic device that contains both RS-232 and RS-485 line drivers and receivers. The configuration of the SP332 can be changed at any time by changing the logic state of two control input pins. The device also includes a loop back function which internally connects driver outputs to receiver inputs for a chip self test. A Sipex-patented charge pump (5,306,954) allows +5V-only operation. RS-232 Mode