A new fast response digital filter control DC-DC converter

A fast and expensive analog to digital signal converter is necessary to realize the fast switching performance in the digitally controlled DC-DC converter. We have already reported the method to use a cheap VCO (voltage controlled oscillator) as an analog to digital converter. However, it has been recognized that this technique is difficult to apply the general digital filter control DC-DC converter because the VCO is useful only for the P-I-D control techniques. So, there has been no study that tried to use both the digital filter control and VCO. This paper presents a new fast response digital filter control DC-DC converter using VCO. Further, the comparison of transient response characteristics of the digital control methods using VCO and the conventional analog to digital signal converter are discussed. As a result, it is revealed that the proposed method has the superior transient response and can suppress the oscillation phenomenon driving from limit cycle.