A new quick response digital control dc-dc converter with dynamic unstable gain

In this paper, we present a new quick response digital control dc-dc converter based on a dynamic unstable gain to improve transient response. In the proposed method, the proportional gain is set to the small value in the steady state and the large value over the stability limit for only a short time in the transient state. Compared with the conventional PID, the undershoot, the overshoot and convergence time are improved by 48%, 71% and 84%, respectively. Generally, when the control gain is set to very large value, the capacitance of output smoothing capacitor must be set to large value simultaneously to maintain the stability of system. That can be reduced and the miniaturization of main circuit can be expected because the very large gain is set for only a short time to improve the transient response in the proposed method.