DC-DC Step-Up Converter using Switched Coupled Inductor

A closed-loop high-gain switched-coupled-inductor switched-capacitor (SCISC) converter is proposed by combining a sawtooth wave generator, pulse-widthmodulation based (PWM based) compensator and nonoverlapping circuit for step-up DC-DC conversion and regulation. The power part between source VS and output VO contains two sub-circuits: (i) a switched-coupled-inductor (SCI) booster circuit, and (ii) a three-stage switched-capacitor (SC) Tripler circuit. With the help of a clamping capacitor and a coupled-inductor with the turn ratio n, this SCI booster can provide the voltage of (2+n-D)/(1-D)VS theoretically, where D means the duty cycle of the MOSFET. And then by using the SC Tripler, the overall step-up gain can reach to 3(2+n-D)/ (1D) at most. Practically, this SCISC can boost the voltage gain up to 37 when D=0.6, n=4. Further, the PWM technique is adopted not only to enhance the output regulation for the compensation of the dynamic error between the practical and desired outputs, but also to reinforce output robustness against source or loading variation. Finally, the closed-loop SCISC is designed by Or CAD SPICE and simulated for some cases: steady-state and dynamic responses. All results are illustrated to show the efficacy of the proposed scheme.