STMicroelectronics STCH03TR, PWM Controller, 23 V, 196 kHz 8-Pin, SO8

The STCH03 current-mode controller is designed for an offline quasi-resonant ZVS (zero-voltage-switching at switch turn-on) flyback converter.
It combines a high-performance low-voltage PWM controller chip and a 650V HV start-up cell in the same package.
The device features a unique characteristic: it is capable of providing constant output current (CC) regulation using primary-sensing feedback. This eliminates the need for dedicated current reference IC, as well as the current sensor, still maintaining quite accurate output current regulation.

Advanced power management for ultra-low standby power consumption (under 10 mW at 230 VAC)
Fully integrated primary side constant current output regulation (CC)
650 V embedded HV start-up circuit with zero power consumption.
Quasi-resonant (QR) zero-voltage-switching (ZVS) operation
Accurate and adjustable output OVP with options auto-restart (STCH03) or latched (STCH03L) after fault
Output undervoltage protection (UVP) with auto-restart