Research And Implementation Of The Performance Improvement Of BUCK Converter

Switch power supply IC already has applied to portable devices and the consumer electronics products broadly. These never stop passing through step , bringing forward new challenges to switch power supply IC design as a result also unceasingly in application to stronger function and longer stand-by time running after.Based on the introduction of the operation theory and basic control mode of the BUCK converters, a discussion of the theories about Hybrid mode for increased the efficiency and input-voltage feedforward for improved dynamic porfermance is presented. Then the controller of BUCK converter with aforesaid methods is designed. According to the application demands the whole architecture is put forward, the working principles of the chip are also explained and the key parameters of the converter is defined. Then the design procedure of some primary function blocks are presented, with the simulation by Hspice.Finally, providing the typical application circuit as the foundation of the simulations for the whole chip, the results of the simulations prove the feasibility of the aforesaid methods.The higher efficiency is one of the most important design guidelines for DC-DC switching regulators all the time. In this thesis the controller IC works in Hybrid mode and is able to change the type of modulation according to the load current. So that the converter can obtain the high efficiency over the wide load range. Furthermore, the input-voltage feedforward control improve the transient response for the input voltage disturbance.The simulations for this design are implemented base on the 0.6μm BCD process. The results indicate that the controller has a fast transient response with small output ripple coefficient and quite fine efficiency up to 85% for a wide range of loads.