Digital Peak Voltage Control of Buck Converter with Multi-sample Technique

Digital control implementation of switching dc-dc converters has benefits of flexibility; however, time delay and quantization errors will degrade the transient performance of switching dc-dc converters due to the degradation of the bandwidth of the digital controller. In this paper, multi-sample technique is proposed as a way to decrease the sample effect in the control loop of switching dc-dc converters. By adopting multi-sample technique and an improved calculation method to decrease the time delay in calculation, a digital platform with improved performance for switching dc-dc converters is established. With ideal transition waveform as dynamic reference, ripple calibration is performed to sense the perturbations by means of sensing the slope of the output voltage ripple. It retrieves the advantage of analog peak voltage control by sensing the perturbations via slope variation. A comprehensive study of the dynamic performance for buck converters with the algorithms has also been performed.