Digital fast-P slow-ID control DC-DC converter

This paper presents a new digital control method for dc-dc converter which consists of two A-D converters with different sampling frequencies. In the presented method, the calculation process of P and ID controls are parallel. The sampling frequency for the P control is higher than the switching frequency and one for ID control is lower than the switching frequency. Therefore, the P control and ID control have different sampling frequency each other. Even in such different setting compared with the conventional PID control method, our presented method can realize the superior transient response. The presented method also contributes the low-cost design of A-D converters. In the experiments, it is obtained that the undershoot of the output voltage and the convergence time are improved by 44% and 78% respectively in the transient response. From the results, it is confirmed that our presented method can provide superior transient characteristics and the low cost implementation simultaneously.