ST3243C

概要

The ST3243B/ST3243C devices consist of 3 drivers, 5 receivers and a dual charge pump circuit. The devices meet the requirements of EIA/TIA and V.28/V.24 communication standards providing high data rate capability and enhanced electrostatic discharge (ESD) protection.

All transmitter outputs and receiver inputs are protected to ±8 kV using IEC61000-4-2 contact discharge and ±15 kV IEC61000-4-2 air discharge.

The receiver R2 is always active to implement a wake-up feature for the serial port.

The ST3243B/ST3243C devices have a proprietary low-dropout transmitter output stage enabling true RS-232 performance from a 3.0 V to 5.5 V supply with a dual charge pump. The devices are guaranteed to run at data rates of 250 kbps while maintaining RS-232 output levels.

The auto-power-down feature functions when FORCEON is low and FORCEOFFis high. During this mode of operation, if the device does not sense a valid RS-232 signal, the driver outputs are disabled. If FORCEOFFis set low, both drivers and receivers (expert R2B) are shut off, and supply current is reduced to 1 μA. Disconnecting the serial port or turning off the peripheral drives causes the auto-power-down condition to occur.

Auto-power-down can be disabled when FORCEON and FORCEOFFare high, and should be done when driving a serial mouse. With auto-power-down enabled, the device is activated automatically when a valid signal is applied to any receiver input.

Typical application are in notebook, subnotebook, palmtop computers, battery-powered equipment, hand-held equipment, peripherals, and printers.