A Synchronous Buck Converter Using a New Predictive Analog Dead-Time Control Circuit to Improve Efficiency

The one-step predictive dead-time control circuit proposed in this paper consists of a dead-time detection circuit and an analog optimization circuit. The detection circuit, which can be manufactured on the same die as the synchronous MOSFET of the buck converter, provides an accurate detection signal that indicates body diode conduction. The proposed dead-time optimization circuit is an analog circuit, which uses the body diode detection signal and eliminates the shortcomings of digital dead-time detection circuits. Operation of the circuit is verified using PSIM. The results of the simulation show that the circuit reduces the body diode conduction time of the synchronous MOSFET to less than 4 ns at 20-A load, 12-V input, 1.2-V output, and 500-kHz switching frequency. As a result, the buck converter conduction losses can be reduced by 16.3%.