A CMOS hybrid control mode DC-DC buck converter for embedded system

A monolithic integrated CMOS DC-DC buck converter is proposed in this paper. The optimum design of the on-chip passive components is concerned to minimize the chip size of the converter. A hybrid control circuit with an easily implemented current sensing block is designed to improve the efficiency of converter having a wide load range. Design consideration, circuit implementation and corresponding simulation results are presented. Simulation results show that the DC-DC converter successfully regulates the input voltage of 3.3 V to output of 1.5 V for load currents from 100mA to 1A with the proposed technique. The maximum efficiency of 76.5% and an output ripple under 5% is achieved. All active and passive components can be fabricated onto a signal chip using the 0.5/spl mu/m double-poly triple-metal CMOS technology.