Large-Signal Transient Responses of a Switching Regulator

Analytical and experimental considerations of the large-signal transient responses of the buck-type switching regulator are described. The dynamic behavior under the large-signal condition is different from the small-signal operation because of the saturation characteristics of the pulsewidth modulator feedback controller. The effect of this nonlinearity is analyzed by dividing its operation into three modes. As a result the peak values of the inrush current and output voltage are obtained analytically both for the start-up and for the step change of the load condition.