High performance digital control algorithms for DC-DC converters based on the principle of capacitor charge balance

In this paper, the principle of capacitor charge balance is utilized to develop high dynamic performance control algorithms for DC-DC converters. Two digital control algorithms are presented which are designed to drive DC-DC converters, (under load current variation or input voltage variation) to their steady-state conditions in optimum time. The proposed algorithms effectively improve the dynamic response of the converter by reducing the output voltage under/overshoot and minimizing the recovery time. The algorithms' key concepts and equations are presented in this paper. Experimental results are presented for a 25 Watt, 400 kHz synchronous Buck converter to verify the effectiveness of both algorithms. The results confirm that the dynamic response of a DC-DC converter is significantly improved (over that of conventional controllers) by implementing the proposed control algorithms.