This part is a kind of semiconductor called AP1703.

Function of this product has (AP1701 - AP1704) 3-PIN MICROPROCESSOR RESET CIRCUITS.

Manufacturers : Diodes Incorporated

Image and pinout :

Some of the text within the PDF file :

AP1701/2/3/4 3-PIN MICROPROCESSOR RESET CIRCUITS Features • • • • • • • • • • • • Precision Monitoring of +2.5V, +3V, +3.3V, and +5V Power-Supply Voltages Fully Specified Over Temperature Available in three Output Configurations Push-Pull RESET Low Output (AP1701/3) Push-Pull RESET High Output (AP1702/4) 200ms Min. Power-On Reset Pulse Width 20µA Supply Current (Typ.) Guaranteed Reset Valid to VCC = +1V Power Supply Transient Immunity No External Components Green Package: SC59-3L Lead Free Finish / RoHS Compliant (Note1) General Description The AP1701/2/3/4 are used for microprocessor (µP) supervisory circuits to monitor the power supplies in µP and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and a [ ... ]

AP1703 PDF Datasheet Download