Design Of Half Bridge LLC Resonant Isolation Power Drive Control Chip

With the continuous development of electronic information,the power supply is developing towards the direction of high power density,high efficiency and lightweight.Improving the operating frequency can effectively optimize these indicators,but it still faces the problem of large switching loss.The resonant converter has become a research hotspot because it is easy to realize soft-switching technology.LLC resonant converter not only can realize soft-switching technology under the full range of load,but also has the advantages of high operating frequency,high efficiency and low EMI noise.On the premise of ensuring the safety of the power supply,it is of great significance to study how to improve the performance of the LLC resonant isolation power drive control chip.Firstly,this dissertation discusses the switching power supply based on the resonant working principle,and expounds the research value of resonant conversion power supply.Through the analysis of the principle and soft-switching function of LLC resonant converter,the key driving control technology of the resonant converter power drive control chip is discussed,and the architecture design and technical indicators of the drive control chip are realized.Secondly,this dissertation based on Nuvoton 0.35μm 40 V BCD process,a half-bridge LLC resonant isolation power drive control chip is designed.The input voltage range is 9-36 V,the adjustable frequency range is 0.1MHz～1.2MHz,the adaptive dead zone time control range is less than 20 ns,and the adjustable dead zone time range is 50ns～1.5μs.The static power consumption is less than 4m A.A novel dead-time control circuit is designed in the drive circuit to improve the range of adjustable dead-time.Through a novel soft start design of oscillator,the inrush current is reduced effectively.A new type of overcurrent detection circuit is designed,which can realize the effective protection of switching overcurrent.In addition,the chip also has undervoltage protection and overtemperature protection function,can be applied to inverter,motor drive,car charger and so on.Finally,theoretical analysis and simulation results of the main unit circuit of the resonant transform power drive control chip are analyzed in this dissertation.On the premise that the sub-module circuit meets the design requirements,the overall simulation verification of the resonant transform power drive control chip is carried out,and finally the layout design of the resonant transform power drive control chip is completed.