The purpose of this paper is to analyze the dynamic characteristics of proposed digital peak current mode dc-dc converter. The waveforms of the output voltage and the reactor current are derived by the small signal analysis. They are compared with simulation results assuming an actual large amplitude operation. It is confirmed that the tendency of the transient response is indicated based on the analysis results. The experimental result of the proposed method shows the validity of the proposed method and a gradual response is obtained by an improvement of the stability of dc-dc converter. Consequently, the proposed method can be a solution of implementing the peak current mode control in digital.