Abstract: The present invention provides improved line and load regulation of a switching-mode power converter (300) without requiring additional capacitors (255), either internally or externally, to stabilize the control loop. The present invention can provide this by integrating a digital compensator (375) with the pulse-width modulator (“PWM”) of the switching-mode power converter. Such a compensator (375) can include comparators (310 and 330), digital circuits (340), and resistors (215, 220, 320, and 325).

Abstract: A circuit that includes a combination of a current resonance type converter of a switching frequency controlling system with a partial-voltage resonance circuit is configured such that, in order to improve the power factor where the load power is 150 W or more and the circuit employs an input double-voltage rectification system, a series resonance capacitor or inductor is connected in series to a tertiary winding wound on the primary side of an isolation converter transformer, so that the voltage is fed back to a rectification circuit composed of a high-speed recovery type diode.