SWITCH CONTROL CIRCUIT, POWER SUPPLY DEVICE COMPRISING THE SAME AND DRIVING METHOD OF THE POWER SUPPLY DEVICE

摘要

The invention relates to a switch control circuit, a power supply including the same, and a method for driving the power supply. The power supply includes: a first switch; a second switch coupled in series to the first switch; a transistor coupled to a node where the first switch and the second switch are coupled; a resonance capacitor coupled between the transformer and a primary side ground and to which a resonance current flows; a sense circuit generating a first sense voltage that depends on the resonance current when the resonance current is a positive current; and a switch control circuit detecting a zero voltage switching failure by sensing the resonance current using the first sense voltage at a turn-off time of the first switch for every switching cycle of the first and second switches.