A high efficiency current-mode DC-DC step-down converter with wide range of output current

This paper presents a high efficiency current-mode DC-DC step-down converter with wide range of output current. The converter adaptively operates as Pulse-Width Modulation (PWM). An on-chip current sensing technique is employed to reduce external components and no extra I/O pins are needed for the current-mode controller. A soft-start operation is designed to eliminate the excess large current during the startup of the regulator. The circuit has been designed with TSMC 2P4M 0.35 μm CMOS process. The range of the supply voltage is from 2 to 5V, which is suitable for single-cell lithium-ion battery.