ST3243: 3.0 TO 5.5 V, 400Kbps RS-232 Transceiver With Auto-powerdown

The ST3243 device consists of 3 drivers, 5 receivers, and ONE dual charge-pump circuit. The device meets the requirements of EIA/TIA-232 and V.28/V.24 communications interface intended for notebook computer applications. The receiver R2 is always active to implement a wake-up feature for the serial port. The ST3243 has a proprietary low-dropout transmitter output stage providing true RS-232 performance from a 3.0V to 5.5V supply with a dual charge pump. The device is guaranteed to run at data rates of 250Kbps while maintaining RS-232 output levels. The auto-power down feature functions when FORCEON is low and is high. In this operating mode if the device does not sense a valid RS-232 signal, the driver outputs are disabled.
If is set to low, both drivers and receivers (expert R2B) are shut off, and supply current is reduced to 1µA. Disconnecting the serial port or turning off the peripheral drivers causes the auto-power down condition to occur.
Auto-powerdown can be disabled when FORCEON and are high, these conditions are necessary when driving a serial mouse. When the device is in Autopower down condition it is active automatically when a valid signal is applied to any receiver input.