Efficiency improvement of triple mode DC-DC Buck converter with adaptive power transistor width (APTW) technique

This article proposes a triple-mode modulation wide input voltage range DC-DC buck converter using adaptive power transistor width (APTW) technique, which can be used in low-power applications such as the Internet of Things and automotive chips. This buck converter operates in PWM mode under heavy loads and switches to PFM mode under light loads. Using a load current detection circuit, it enters power-saving mode (PSM) at extremely light loads and adaptively adjusts the power transistor width to minimize circuit losses. The proposed buck converter is designed using a 0.18μm standard CMOS process. Simulation results show that when a 12V standard input voltage is used to generate a 5V output voltage, the efficiency reaches up to 94% for load currents in the 1mA-1A range, and the converter maintains a high efficiency of 80% at light loads of 1mA.