A monolithic capacitor-current-controlled hysteretic buck converter with transient-optimized feedback circuit

Abstract

This paper proposes a monolithic capacitor-current-controlled hysteretic buck converter with a transient-optimized feedback circuit (TOFC) and a transient-hold (TH) technique. The proposed TOFC simultaneously optimizes both load and dynamic voltage scaling (DVS) transient responses. In addition, the proposed TH technique significantly reduces the required compensation capacitance to save chip area. Implemented in a 0.35-μm CMOS process, this work occupies 0.88 mm2. Measured results show that, for 500-mA step-up load current, output voltage is settled within 0.9 μs, and for 0.6-V DVS, output voltage is settled within 3 μs. Peak efficiency of 96% is measured at 500 mW output power.