The ADM222, ADM232A, ADM242 are a family of high speedRS-232 line drivers/receivers offering transmission rates up to200 kB/s. Operating from a single +5 V power supply, a highly efficient on-chip charge pump using small (0.1μF) external capacitors allows RS-232 bipolar levels to be developed. TwoRS-232 drivers and two RS-232 receivers are provided on each device.The devices are fabricated on BiCMOS, an advanced mixed technology process which combines low power CMOS with high speed bipolar circuitry. This allows for transmission rates up to200 kB/s yet minimises the quiescent power supply current to under 5 mA.The ADM232A is a pin-compatible, high speed upgrade for theAD232 and for the ADM232L. It is available in 16-pin DIP and in both narrow and wide surface mount (SOIC) packages.The ADM222 contains an additional shutdown (SHDN) func-tion which may be used to disable the device thereby reducing the supply current to 0.1 μA. During shutdown, all transmit/receive functions are disabled. The ADM222 is available in18-pin DIP and in a wide surface mount (SOIC) package.The ADM242 combines both shutdown (SHDN) and enable(EN) functions. The shutdown function reduces the supply current to 0.1 mA. During shutdown, the transmitters are disabled but the receivers continue to operate normally. The Enable function allows the receiver outputs to be disabled thereby facilitating sharing a common bus. The ADM242 is available in 18-pin DIP and in a wide surface mount (SOIC)package.