Patent ID: 8582329

Claim:
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 switch 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, the switch controller monitoring a sensed voltage representing an output voltage of the switching power converter, and the switch controller configured to control switching of the switch to operate the switching power converter in a continuous conduction mode while the sensed voltage indicates that the output voltage is less than a first threshold voltage, the switch controller further configured to control switching of the switch to operate the switching power converter in an open loop discontinuous conduction mode while the sensed voltage indicates that the output voltage is above the first threshold voltage and below a second threshold voltage, wherein the switching controller controls switching of the switch independently of the sensed voltage when in the open loop discontinuous conduction mode, and the switch controller configured to control switching of the switch to operate the switching power converter in a closed loop discontinuous conduction mode while the sensed voltage indicates that the output voltage is above the second threshold voltage, wherein the first threshold voltage and the second threshold voltage are less than a desired regulation voltage of the switching power converter.