This part is a kind of semiconductor called AX3304.

Function of this product has PWM Control Controller.

Manufacturers : AXElite

Image and pinout :

Some of the text within the PDF file :

AX3304 PWM Control Controller  GENERAL DESCRIPTION The AX3304/A integrates Pulse-Width-Modulation (PWM) control circuit into a single chip, mainly designs for power-supply regulator. All the functions include an error amplifier, a soft-start, UVLO, OVP, SCP, TSD circuitry. This device features an internal 100KHz oscillator (300KHz for "A" version), the UVLO makes sure that the outputs are off until the internal circuit operates normally.  FEATURES - Input voltage：8V to 40V - Duty ratio：0% to 100% PWM control - Oscillation frequency：100K/300KHz Thermal Shutdown function. Short Circuit Protect (SCP). External SW P-channel MOS. € •yÑb External OVP setting function. R ` w m VÛm Current mode non-synchronous PWMo converter - External current limit setting. tech fo - Under vol [ ... ]

AX3304 PDF Datasheet Download