A switch-utilization-improved switched-inductor switched-capacitor converter with adapting stage number

作者：Chang Yuen Haw^*; Chen Yu Jhang

来源：International Journal of Circuit Theory and Applications, 2016, 44(3): 709-728.

DOI：10.1002/cta.2102

• switched-inductor
• switched-capacitor
• step-up converter
• switch utilization
• adaptive-stage-number (ASN)
• pulse-width-modulation (PWM)

A novel closed-loop switched-inductor switched-capacitor converter (SISCC) is proposed by using the pulse-width-modulation (PWM) compensation for the step-up DC-DC conversion/regulation, and together by combining the adaptive-stage-number (ASN), control for the higher switch utilization and wider supply voltage range. The power part of SISCC is composed of two cascaded sub-circuits, including (i) a serial-parallel switched-capacitor circuit with n(c) pumping capacitors and (ii) a switched-inductor booster with m(c) resonant capacitors, so as to obtain the high step-up gain of (n(c)+1)xm(c)/(1-D) at most, where D is the duty cycle of PWM adopted to enhance output regulation as well as robustness to source/loading variation. Besides, the ASN control is presented with adapting the stage number n (n=0,1,2,...,n(c)) of pumping capacitors to obtain a flexible gain of (n+1)xm(c)/(1-D), and further in order to make the SISCC operating at a properly small duty cycle for improving switch utilization and/or supply voltage range. Some theoretical analysis and control design include formulation, steady-state analysis, ASN-based conversion ratio, efficiency, output ripple, stability, inductance and capacitance selection, and control design. Finally, the performance of this scheme is verified experimentally on an ASN-based SISCC prototype, and all results are illustrated to show the efficacy of this scheme.

• 出版日期2016-3