A new digital peak current control for DC-DC converter with fast P control and IIR filter

The purpose of this paper is a new digital peak current control for the dc-dc converter with a fast proportional (P) control and IIR filter. The proposed control circuit has two features. First, a simple A-D converter for the peak current detection is used. It is consist of an RC integrator and delay circuit. The sampling point of detected current is changed by the feedback value of output voltage. It can detect the peak current in real time. Second, the digital feedback control for the output voltage combines the fast P control and IIR filter. The fast P control can decrease the delay time and improve the transient response. As a result, the proposed method shows that the convergence time and undershoot of output voltage are improved by about 80% and 70% compared with the conventional digital voltage mode control, respectively.