The PD4722 is a high-breakdown voltage silicon gate CMOS line driver/receiver based on the EIA/TIA-232-E standard. The internal DC/DC converter can switch between multiple voltages, allowing it to operate with a single +3.3 V or +5 V power supply. It also provides standby function. This IC incorporates 4 driver circuits and 4 receiver circuits. An RS-232 interface circuit can be easily configured by connecting 5 capacitors externally.