This part is a kind of semiconductor called L6599A.

Function of this product has Improved high-voltage resonant controller.

Manufacturers : STMicroelectronics

Image and pinout :

Some of the text within the PDF file :

L6599A Improved high-voltage resonant controller Features ■ 50% duty cycle, variable frequency control of resonant half bridge ■ High-accuracy oscillator ■ Up to 500 kHz operating frequency ■ Two-level OCP: frequency-shift and latched shutdown ■ Interface with PFC controller ■ Latched disable input ■ Burst mode operation at light load ■ Input for power-ON/OFF sequencing or brownout protection ■ Non-linear soft-start for monotonic output voltage rise ■ 600 V-rail compatible high-side gate driver with integrated bootstrap diode and high dv/dt immunity ■ -300/800 mA high-side and low-side gate drivers with UVLO pull-down ■ DIP16, SO16N package Applications ■ LCD and PDP TV ■ Desktop PC, entry-level server ■ Telecom SMPS ■ High efficiency industrial SMPS ■ A [ ... ]

L6599A PDF Datasheet Download