This part is a kind of semiconductor called D4723GS.

Function of this product has UPD4723GS.

Manufacturers : NEC

Image and pinout :

Some of the text within the PDF file :

DATA SHEET MOS INTEGRATED CIRCUIT µPD4723 RS-232 LINE DRIVER/RECEIVER AT 3.3 V/5 V The µPD4723 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 3 driver circuits and 3 receiver circuits. An RS-232 interface circuit can be easily configured by connecting 5 capacitors externally. Features • Conforms to EIA/TIA-232-E (former name, RS-232C) standards • Selectable +3.3 V/+5 V single power supply (selected by VCHA pin) • By setting the standby pin to a low level (standby mode), circuit current can be reduced. At such times, the driver output is [ ... ]

D4723GS PDF Datasheet Download