Fully digital voltage-mode control based on predictive hysteresis method (FDVC-PH) for DC-DC converters

A new control method called “fully digital voltage-mode control based on predictive hysteresis method” (FDVC-PH) for DC-DC converters was developed. FDVC-PH achieves low output ripple voltage by canceling the delay time caused by a digital control system. Moreover, to cancel the delay time completely, a technique for determining the required predictive time by analyzing predictive operation in frequency domain is proposed. To verify the effectiveness of FDVC-PH, a buck converter was experimentally implemented on a DSP microprocessor. The output ripple voltage of the converter is reduced by 68% with FDVC-PH compared to that with a non-predictive hysteresis method. Moreover, the power consumption of a digital control system using FDVC-PH is reduced by 23% compared to that of a system using conventional digital current-mode control.