LM5156: Schematic check request

Hi Tommy, thanks for using E2E.

I checked the schematic and it seems to be ok. Maybe the loop compensation has to be adjusted once the design is built.

Two points i found:

1. I would recommend to add a PNP transistor to the primary side softstart like in below picture. This will limit the duty cycle also in the first switching cycles.

2. In your design you supply VCC externally with an AUX winding. The transistor of the optocoupler is pulled up to this voltage. In case of voltage variations, the regulation can be affected. To avoid this, a zener diode can be used to clamp the pullup voltage to a certain level:

Best regards,

Moritz