High frequency and high efficiency DC-DC converter with sensorless adaptive-sizing technique

Abstract

A high frequency and high efficiency DC-DC converter with sensorless adaptive-sizing technique is proposed. Instead of conventional adaptive-sizing technique with current sensor, the proposed converter estimates the load current according to the output voltage of error amplifier for switch scaling. The elimination of current sensor reduces power consumption, thus improving efficiency further. This design is validated through simulation in a 0.18 µm CMOS process. At switching frequency of 150 MHz and light-load of 20 mA, the proposed converter achieves a high efficiency of 82.4%, while it is 73.7% with conventional adaptive-sizing technique, and 62.4% without adaptive-sizing technique.