A Peak-Valley Current-Mode Buck Converter With 3% to 95% Duty Cycle

A peak-valley current-mode (PVCM) Buck converter is presented to extend the duty cycle range. Compared with traditional single inductor current-controlled converters, the PVCM Buck converter employs both the peak inductor current (PIC) and the valley inductor current (VIC) to precisely regulate the output voltage. Additionally, the converter features a voltage-controlled delay circuit, to enable active adjustment of operating frequency and to extend the duty cycle range. The proposed converter is implemented using a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.18\mu $ </tex-math></inline-formula>m BCD process. Experimental results demonstrate that the prototype achieves the 3% to 95% duty cycle range with a peak efficiency of 92%.