SP336E

SP336E 3.3V - 5V PROGRAMMABLE RS-232/RS-485/RS-422 SERIAL TRANSCEIVER MARCH 2010 REV. 1.0.0 GENERAL DESCRIPTION The SP336E is a monolithic serial multi-transceiver device that contains both RS-232 and RS-485/RS422 line drivers and receivers. The configuration of the SP336E can be reconfigured into eight operating modes including RS-232 only (4TX/4RX), RS-485/ RS-422 only (2TX/2RX) full or half duplex, two RS232/RS-485 mixed modes. two shutdown modes and a diagnostic loop-back mode. Modes may be selected at any time by changing the logic state of the three MODE pins. The device can implement a dualmode serial port, mixed mode ports or as an interface signal translator. The Exar charge pumps deliver true RS-232 driver output voltages from a single power supply at either 3.3V or 5V. The SP336E requires only four 0.1μF capacitors for charge pump. A slew rate control pin configures driver outputs for either high data rate or slew-controlled data rates. Slewcontrolled outputs minimize problems with reflections and ringing on long or un-terminated cables. All RS485 receivers or transceivers feature high impedance which allow up to 256 transceivers on a shared bus. When configured in RS-485/RS-422 mode, each driver may be individually enabled or put into tri-state, simplifying use on shared buses or bidirectional communication. All receivers have advanced failsafe protection to prevent oscillation when inputs are unconnected. In RS-232 mode each receiver input has a 5k ohm pull-do...