Current Zero Crossing Detection Circuit for Synchronous Rectification Model Buck Converter

Abstract

In order to reduce the power consumption of the synchronous rectification model buck converter, a current zero crossing detection circuit is designed in this paper. The detection circuit determines the freewheeling current of the synchronous rectification power switch is zero or not by detecting the drain voltage of synchronous rectification power switch. Due to use transistors instead of resistors in the voltage conversion, the accuracy of the detection circuit is less affected by temperature and process corner. From the experimental results, the detection circuit can make accurate current zero crossing detection in different temperatures and process corners, and the detection circuit has strong robustness.

Design of adjustable voltage power supply based on buck

“…Synchronous rectifier circuit uses MOS tube with low on-state impedance to replace conventional continuous current diode, through the control circuit output 180° complementary PWM wave to drive the switching MOS tube and the continuous current MOS tube, eliminate the reverse peak current at the end of the continuation, reduce the loss of the rectifier circuit, improve the conversion efficiency of the power supply, and can meet the needs of large current applications [10][11] . At the same time, the voltage can be adjusted by using the control system, and the voltage feedback can control the accuracy of the output voltage [12][13][14][15] .The design based on the Buck synchronous rectifier circuit schematic diagram is shown in Figure 2.…”