Abstract: Considering the issue of the large output voltage ripple of Pulse Skip Modulation (PSM) controlled switching DC-DC converter, a novel control technique named Pulse Skip with Adaptive Duty ratio (ADPS) is proposed in this paper. In ADPS converter with light load, the duty ratio of control pulse of each switching cycle is approximately proportional to the square root of the voltage error between the reference voltage and the output voltage at the beginning of the switching cycle. Also, the lighter the load is, the smaller the ripple is. The experimental results show that ADPS converter not only has lower output voltage ripple than PSM converter, but also has excellent control robustness and transient performance.