Patent ID: 9444364
Filing Date: 2016-09-13
CPC Classification: H02M

Claim Text:
1. A switching power converter comprising: a transformer including a primary winding coupled to an input voltage and a secondary winding coupled to an output of the switching power converter; a switch coupled to the primary winding of the transformer, current through the primary winding being generated while the switch is turned on and not being generated while the switch is turned off; and a controller configured to generate a control signal to turn on or turn off the switch, the switch being turned on responsive to the control signal being in a first state and the switch being turned off responsive to the control signal being in a second state, wherein: responsive to an occurrence of a local minimum of a voltage across the switch and a current level at the output of the switching power converter being greater than a first current level but less than a second current level, the second current level being greater than the first current level, the controller is further configured to generate the control signal based on a first operation mode; responsive to satisfying a voltage-time product condition and a current at the output of the switching power converter being greater than the second current level but less than a third current level, the third current level being greater than the second current level, the controller is further configured to generate the control signal based on a second operation mode; and wherein at a transition point between the first operation mode and the second operation mode, the controller is further configured to use a voltage-time product of the transformer prior to transitioning to the second operation mode as a reference point to determine a turn-on time of the switch during the second operation mode.