US Patent 9444364 Adaptive peak power control

A switching power converter includes a controller configured to transition from a first operating mode to a second operating mode by determining the operating conditions at the transition point between the operation modes. The controller uses the value of the voltage-time product determined at the boundary between the first and second operating modes to predict the voltage to be applied to the primary-side of the transformer. Using the predicted voltage, the controller can adjust the peak-power control threshold on a cycle-by-cycle basis without the transformer reaching saturation.