DESCRIPTION
The SP331 is a programmable RS-232 and/or RS-485 transceiver IC. The SP331 contains four drivers and four receivers when selected in RS-232 mode; and two drivers and two receivers when selected in RS-485 mode. The SP331 also contains a dual mode which has two RS-232 drivers/receivers plus one differential RS-485 driver/receiver.
The RS-232 transceivers can typically operate at 230kbps while adhering to the RS-232 specifications. The RS-485 transceivers can operate up to 10Mbps while adhering to the RS-485 specifications. The SP331 includes a self-test loopback mode where the driver outputs are internally configured to the receiver inputs. This allows for easy diagnostic serial port testing without using an external loopback plug. The RS-232 and RS-485 drivers can be disabled (High-Z output) by controlling a set of four select pins.

FEATURES
■ +5V Only Operation
■ Software Programmable RS-232 or RS-485 Selection
■ Four RS-232 Transceivers in RS-232 Mode
■ Two RS-485 Full-Duplex Transceivers in RS-485 Mode
■ Two RS-232 Transceivers and One RS-485 Transceiver in Dual Mode
■ Self-Testing Loopback Mode
■ Full Driver Tri-State (Hi-Z) Control
■ Ideal for RS-232 to RS-485 conversion