A wide load range high-efficiency DC-DC based on fast multi-frequency switch

A full load range high efficiency DC-DC converter with fast current detection (CD) and frequency adjustment (FA) operation is proposed in this paper. According to the analysis, the losses of DC-DC converter are most related to the switching loss of MOSFET, and the regulation of frequency is the main method to reduce the loss. In order to achieve high efficiency, the oscillator designed has three different frequencies and the FA selects the appropriate frequency for DC-DC system according to the value of load current. The CD could detect the change of load current and put them into several stages with a fast way to promote the response speed when the load current changes. This structure can achieve high efficiency and maintain a low ripple at a wide load range (10mA to 2.5A).