Accurate Dead-Time Control for Synchronous Buck Converter With Fast Error Sensing Circuits

Abstract

Dead-time controls for synchronous buck converter are challenging due to the difficulties in accurate sensing and processing the on/off dead-time errors. For the control of dead-times, an integral feedback control using switched capacitors and a fast timing sensing circuit composed of MOSFET differential amplifiers and switched current sources are proposed. Experiments for a 3.3 V input, 1.5 V-0.3 A output converter demonstrated 1.3 ~ 4.6% efficiency improvement over a wide load current range.