Abstract: A constant frequency pulse-width modulator that realizes various control schemes with trailing-edge, leading-edge or double-edge modulation is disclosed. This PWM modulator, which employs one or more integrator with reset stages, can be generally applied to implement feed-forward control of a family of converters, current mode control with linear or non linear compensating slope, and a family of unity-power-factor rectifiers at continuous or discontinuous conduction mode.

Abstract: A one cycle control for controlling DC-to-AC switching converters is achieved by forcing the average of a controlled switched variable to be exactly equal to the control reference in each switching cycle. Potential subharmonic oscillations in a switching power amplifier which occurs in the DC-to-AC application of this method is prevented by adding an offset voltage to the averaged controlled switched variable which is fed back and compared to a control reference, which compares and is then used to switch the switching power amplifier. Switching errors are corrected by resetting the integrator which averages the controlled switched variable and a time interval at least an order or magnitude less than the switching time of the switches in the switching power amplifier.