The ST3232BDR has two receivers and two drivers,  and a dual charge-pump circuit. 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 3.0V to 5.5V supply.  The device operates at data signaling rates up to 250kbit/s and a  maximum of 35V/μs driver output slew rate.

The MAX232E have two drives and two receivers. The drivers and receivers meet all EIA/TIA-232E  and CCITT V.28 specifications at data rates up to 120 kbps when loaded in accordance with the  1  EIA/TIA-232E specification

The MAX3232IDR has two receivers and two drivers, and a dual charge-pump circuit.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 3.0V to 5.5V supply. The device operates  at data signaling rates up to 250kbit/s and a maximum of 35V/μs driver output slew rate.

The MAX3232ESE has two receivers and two drivers,  and a dual charge-pump circuit. 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 3.0V to 5.5V supply.  The device operates at data signaling rates up to 250kbit/s and a  maximum of 35V/μs driver output slew rate.