A novel pulse shift modulation technique for controlling DC-DC converters

Pulse Width Modulation technique (PWM) and Pulse Frequency Modulation technique (PFM) are commonly used techniques to generate pulses to control switches in DC-DC converters. However, these techniques generate various losses as well as output fluctuations when used at wide load ranges. The conduction losses and output voltage ripples are dominant in PWM at high loads, and switching losses are dominant in PFM at low loads. Therefore, this paper proposes a novel modulation technique, which dynamically changes the duty cycle and frequency of the control pulse to control these switches in DC-DC converters. The results show that the proposed technique reduces the conduction losses and ripple voltage inherent in PWM and switching losses inherent in PFM, thus improves the efficiency of the converters at wide load ranges.