This part is a kind of semiconductor called APX803.

Function of this product has 3-PIN MICROPROCESSOR RESET CIRCUIT.

Manufacturers : Diodes

Image and pinout :

Some of the text within the PDF file :

APX803 3-PIN MICROPROCESSOR RESET CIRCUIT Features • Precision Monitoring of +2.5V, +3V, +3.3V, and +5V Power-Supply Voltages • Fully Specified Over Temperature • Available in three Output Configurations • Open-drain RESET Active Low • 200ms Typ Power-On Reset Pulse Width • 30µA Supply Current (Typ.) • Guaranteed Reset Valid to VCC = +1V • No External Components • SOT23 and SOT23R: Available in “Green” Molding Compound (No Br, Sb) • Lead Free Finish/ RoHS Compliant (Note 1) General Description The APX803 is 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 adjustments when used with +5V, +3.3V, +3.0V powered cir [ ... ]

APX803 PDF Datasheet Download