고정된 주파수를 갖는 듀얼 히스테리틱 벅 변환기

초록

This paper presents a hysteretic buck CMOS converter with dual modes (CCM and DCM) and with a fixed switching frequency. The proposed converter employs CCM in a High Fixed Switching Frequency operation and DCM in a Low Fixed Switching Frequency operation. This dual mode allows the proposed converter to enhance the power efficiency in a Low Switching Frequency operation. It is capable of generating an output voltage of 1.2V with input voltage range of 3.3~4.5V. The proposed circuit is implemented with a 180nm BCDMOS process. The simulated output ripple voltage in CCM and in DCM are 3.77mV and 4.33mV respectively. Transient response time remains within 5.74µs. The simulated power efficiencies in DCM and CCM are 78% and 94%, respectively.