High Power Efficiency, 8 V Similar To 20 V Input Range Dc-Dc Buck Converter With Phase-Locked Loop

This paper presents a DC-DC buck converter with Phase-Locked Loop (PLL) to generate the constant switching frequency regardless of Process, Voltage, Temperature (PVT) variations. When the input range is from 8 V to 20 V, the proposed DC-DC buck converter with PLL is implemented to have over 90 % efficiency in heavy load current of 1.0 A. also to reduce the size of the external device while maintaining high efficiency, 2 MHz switching frequency and 2.2 mu H inductance were used. The proposed DC-DC buck converter with PLL to generate constant frequency to compensate for the efficiency variation. As a result, the efficiency variation is less than 1 %. This chip was fabricated using 0.18 mu m BCD technology, and the area is 3.96 mm(2). The maximum efficiency of proposed DC-DC buck converter with PLL is 92.53 %.