The MAX3221 device consists of one line driver, one line receiver, and a dual charge-pump circuit with 15-kV ESD protection pin to pin (serial-port connection pins, including GND). The device meets the requirements of TIA/EIA-232-F and provides the electrical interface between an asynchronous communication controller and the serial-port connector. The charge pump and four small external capacitors allow operation from a single 3-V to 5.5-V supply. These devices operate at data signaling rates up to 250 kbit/s, and at a maximum of 30-V/s driver output slew rate.