Circuit Diagram Note: A complete schematic is available in the original PDF, but the typical topology is a quasi-resonant or fixed-frequency flyback with a 67kHz switching frequency.
Engineers frequently report the following problems when using the STR-F6267: str f6267 datasheet pdf
| Symptom | Likely cause per datasheet | Solution | |------------------------------|-----------------------------------------------------|--------------------------------------------| | No startup, VCC oscillates | VCC startup capacitor too small or leakage | Increase to 47µF, check startup resistor | | Supply shuts down under load | Current sense resistor too large (false OCP) | Reduce resistor value (e.g., 0.33Ω→0.27Ω) | | Blown IC | Drain overvoltage spike exceeding 650V | Improve snubber, check transformer leakage | | Intermittent restart | Overload protection triggered by noise on FB pin | Add 100pF capacitor from FB to GND | Circuit Diagram Note: A complete schematic is available
When you download the STR F6267 datasheet PDF, focus on the following sections: focus on the following sections: