What about 5V ? Is it stable 5V or 4.9 for example?
Цитата:
Power-OK signal output pin. This pin is an open-drain output used to indicate the
status of output voltage by sensing FB voltage. This pin is pulled low when output
voltage is not within the Power-OK voltage window.
Open drain, so maybe you don't have a pullup? It may be LOW or tristated. Tristated requires a pullup.
