A 5-MHz 91% peak-power-efficiency buck regulator with auto-selectable peak- and valley-current control

This paper presents a multi-MHz buck regulator for portable applications using an auto-selectable peak- and valley-current control (ASPVCC) scheme. The proposed ASPVCC scheme and the dynamically-biased shunt feedback in the current sensors relax the settling-time requirement of the current sensing and improve the sensing speed. The proposed converter can thus operate at high switching frequencies with a wide range of duty ratios for reducing the required inductance. Implemented in a 0.35-μm CMOS process, the proposed buck converter can operate at 5-MHz with a duty-ratio range of 0.6, use a small-value off-chip inductor of 1 μH, and achieve 91% peak power efficiency.