An automatic load-adaptive switching frequency selection technique for improving the light-load efficiency of a buck converter

作者：Moon Young Jin^*; Roh Yong Seong; Yoo Changsik

来源：Analog Integrated Circuits and Signal Processing, 2013, 75(3): 349-358.

DOI：10.1007/s10470-013-0056-4

• DC-DC buck converter
• Light-load condition
• Power efficiency
• Switching frequency selection
• Load-adaptive

A load-adaptive automatic switching frequency selection scheme is proposed to improve the power efficiency of a switching buck converter at light load condition. The buck converter operates in the continuous-conduction mode for heavy loading and the switching frequency is fixed at its maximum value. For light loading, the buck converter operates in the discontinuous-conduction mode and its switching frequency is automatically selected among a pre-defined set of frequencies according to the amount of the load current. The load current can be sensed indirectly by monitoring the on-time of power transistor because it is a function of the load current. With the proposed load-adaptive automatic switching frequency selection circuit, the power efficiency of a buck converter implemented in a 0.35-mu m 2P4M BCDMOS technology is improved by 24.0-% when the load current load is 10-mA.

• 出版日期2013-6