BUY UC3907N https://www.utsource.net/itm/p/11743517.html

Description: The UC3907N is a high performance current-mode PWM controller designed for off-line and DC-to-DC converter applications. Features: Current-mode control Internal soft-start Internal oscillator Under-voltage lockout Over-current protection Over-temperature protection Low start-up current Low shutdown current Low operating current Wide operating voltage range Applications: Off-line converters DC-to-DC converters Switching power supplies Battery chargers Motor control (For reference only)