A standard application for the STR W6553A is an isolated flyback power supply. Below is a simplified description of the external components:
The device features a 7-pin layout with the following primary functions: High-voltage power input. Source/Ground: Common ground connection. VCC (Power): Supply voltage for the control IC. Soft-start and overload protection timing. FB (Feedback): Voltage regulation control. Bottom Check: Signal for quasi-resonant switching timing. direct equivalents for this IC? STR-W6553A SANKEN Discrete Semiconductors - Jotrin str w6553a datasheet