A Novel High Resolution DPWM Circuit for High Frequency Digitally Controlled DC-DC Converter

This paper presents a novel high resolution DPWM circuit for 1MHz digitally controlled dc-dc converter. The switching power supply is required the small size and light weight. Generally, it is possible to miniaturize the passive element by increasing the switching frequency of the switching power supply. However, the clock frequency must be further increased in order to use the digital control switching power supply in the high switching frequency because the PWM signal is generated by counting the clock signal. As a result, the CMOS structure of DPWM signal generator increases power consumption as the frequency rises. The cost of the control circuit itself increases as well. Therefore, in this paper, we propose the DPWM signal generator with better resolution than the conventional method, and with the simple structure which consists of D-A converter and RC circuit. In the simulation, the proposed method can improve the resolution of the PWM signal. Further, experiments of the proposed method are conducted partly to confirm the effectiveness.