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 ±15 kV IEC61000-4-2 air discharge.The receiver R2 is always active to implement a wake-up feature for 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 andFORCEOFFis high. During this mode of operation, if the device does not sense a valid RS-232 signal, the driver outputs are disabled. IfFORCEOFFis set low, both drivers and receivers (expert R2B) are shut off, and supply current is reduced to 1 mA. 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 andFORCEOFFare 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, handheld equipment, peripherals and printers.ESD protection for RS-232 I/O pins±8 kV IEC61000-4-2 contact discharge±15 kV IEC61000-4-2 air discharge1 µA supply current achieved when in auto-power-down250 kbps minimum guaranteed data rateGuaranteed 6 V/µs slew rate rangeGuaranteed mouse drive ability0.1 µF external capacitorsMeet EIA/TIA-232 specifications down to 3 VAvailable in SSOP-28 package