Class D Series-Resonant DC/DC Converter Using Switch-Controlled Capacitor with ON-OFF Feedback Control

This paper proposes a class D series-resonant DC/DC converter using switch-controlled capacitor (SCC) with ON-OFF feedback control. The proposed class D inverter can control the output voltage by using the ON-OFF control in the switch-controlled capacitor. Impedance variation owing to the SCC maintains the output voltage at a constant value when load fluctuation occurs at a fixed switching frequency. The SCC is turned on when the voltage difference between the two capacitors becomes zero to prevent inrush current between the capacitors. This paper also provides a design example of the proposed class D series-resonant DC/DC converter using switch-controlled capacitor with feedback control. Experimental results show the proposed method can control the output voltage between 6.08 V and 7.43 V. It is also confirmed that the proposed ON-OFF feedback control kept the constant output voltage after a 20% load fluctuation. The experimental results verify the relevance of the proposed method.