The ADM222， ADM232A， ADM242 are a family of high-speed RS-232 line drivers/receivers offering transmission rates up to 200 kB/s. Operating from a single 5 V power supply， a highly efficient on-chip charge pump using small （0.1 μF） external capacitors allows RS-232 bipolar levels to be developed. Two RS-232 drivers and two RS-232 receivers are provided on each device. The devices are fabricated on BiCMOS， an advanced mixed technology process that combines low power CMOS with highspeed bipolar circuitry. This allows for transmission rates up to 200 kB/s， yet minimizes the quiescent power supply current to under 5 mA. The ADM232A is a pin-compatible， high-speed upgrade for the AD232 and for the ADM232L. It is available in 16-lead DIP and in both narrow and wide surface-mount （SOIC） packages. The ADM222 contains an additional shutdown （SHDN） function that may be used to disable the device， thereby reducing the supply current to 0.1 μA. During shutdown， all transmit/receive