The MAX3221CAE+ is a RS-232 Transceiver for handheld equipment. The MAX3221 achieve 1μA supply current with Maxim's revolutionary AutoShutdown? feature. When the MAX3221 do not sense a valid signal level on their receiver inputs, the on-board power supply and drivers shut down. This occurs if the RS-232 cable is disconnected or if the transmitters of the connected peripheral are turned off. The system turns on again when a valid level is applied to any RS-232 receiver input. The MAX3221 require only 0.1μF capacitors in 3.3V operation and can operate from input voltages ranging from +3.0 to +5.5V. A proprietary, high-efficiency, dual charge-pump power supply and a low-dropout transmitter combine to deliver true RS-232 performance from a single +3.0 to +5.5V supply.
Integrated charge pump circuitry simplifies power requirements