Circuit Analysis And Design Of High Efficiency Switch Mode Power Supply

The emergence of the COVID-19 has gradually changed people’s work and lifestyle.At the same time,with the vigorous development of Internet technology,the demand and use of electronic products,especially consumer electronic products and communication products,are increasing day by day.These electronic products are essential for high efficiency.The demand for low-power power management integrated circuits is becoming stronger.In this context,this article studies some methods to improve the efficiency of switching power supplies.This thesis analyzes and calculates the loss model of the switch mode power supply,designs and implements four circuit modules that are essential to improve the switch mode power supply system,including level shifters,bootstrap circuits,adaptive zero-crossing detection circuits and adaptive dead-time control.In this thesis,after investigating the research status of these four circuit modules,a detailed analysis and design are carried out.First,the loss model of BUCK DC-DC converter is calculated and analyzed,and hen the loss model of the three-level switching converter is calculated and analyzed.For the level shifter,this thesis proposes two floating voltage level shift circuits,which can maintain high-speed and low-power performance and high-efficiency area,while eliminating the common-mode current generated by power swing,greatly improving the circuit Ability to resist power swing.The proposed double cross-coupling structure level shift circuit has a post-simulation result of 15V/5ps after its anti-power swing performance,and the propagation delay is only 0.5ns.For the bootstrap circuit,this thesis designs a bootstrap circuit that can adaptively boost the voltage following the input voltage.The post-simulation results show that the circuit can provide a stable power supply for the switch mode power supply drive circuit.For the adaptive zero-crossing detection circuit,this article refers to the corresponding literature,gives the circuit parameter analysis and selection strategy,and realizes a zero-crossing detection circuit that can accurately detect.For dead-time control,this thesis analyzes its loop in detail,and realizes an adaptive dead-time control circuit that can automatically follow the load change.