This part is a kind of semiconductor called AS2333.

Function of this product has (AS23xx) Secondary Side Housekeeping Circuit.

Manufacturers : Astec

Image and pinout :

Some of the text within the PDF file :

SEMICONDUCTOR AS23xx Secondary Side Housekeeping Circuit Description The AS23xx is a housekeeping circuit for monitoring the outputs of power supplies. It directly senses all the output rails without the need for external dividers and detects undervoltage and overvoltage. It also provides an additional undervoltage comparator which may be configured with any arbitrary hysteresis to sense a divided down representation of the AC bulk voltage. The housekeeping section provides all the features necessary to allow external caps to set the common timing features of PC type power supplies. In addition, negative rails may be sensed without the necessity of a VEE connection, and negative sensing may be disabled without affecting operation of the positive sense section. The 2.5 V series reference i [ ... ]

AS2333 PDF Datasheet Download