This part is a kind of semiconductor called ZT3243E.

Function of this product has 3D/5R 250kbps RS232 Transceivers.

Manufacturers : Zywyn

Image and pinout :

Some of the text within the PDF file :

ZT3243E Low Power +3V to +5.5V, 3D/5R 250kbps RS232 Transceivers Zywyn Corporation Zywyn ZT3241E/ZT3243E ZT3241E/ZT3243E Low Power +3V to +5.5V, 3D/5R 250kbps RS232 Transceivers Features • Meets or Exceeds the EIA/TIA-232F and CCITT V.28/V.24 Specifications for VCC at +3.3V ±10% and +5V ±10% Operations • Interoperable with EIA/TIA-232 and adheres to EIA/TIA-562 down to a +2.7V power source • Low quiescent current – 0.5mA typ., 1mA max. • Low shutdown current (where applicable) - 1μA typical, 10μA max. • Guaranteed data rate 250kbps • Proprietary Switch-Capacitor Regulated Voltage Converters (patent pending) • Proprietary AUTOGREEN Power Saving (patent pending) • Latch-up Free • ESD Protection for RS-232 I/O's ±15kV Human Body Model (HBM) ±15kV IEC61000-4-2 Air [ ... ]

ZT3243E PDF Datasheet Download