Study Of DC-DC Converter Power Dissipation And Implement Of Hybrid Mode Buck Chip

Widely used portable devices, the rapid process for computer, communication and automobile industry actuate constantly the advancement of the technique of switching power supply. As the application field expanded, the demand on high efficiency, high reliability and high power density becomes the new design challenge to switching power supply IC.Based on the in-deep study of the interrelated technique of the DC-DC buck converters, a design scheme of the switching regulator of dual-mode PWM/PFM buck converters operating at a fixed frequency of 1.25MHz is presented. According to the application demands a specification is put forward, the working principles of the converter are also explained. By consideration the key factors of the circuit design the structure of the converter is defined, then the design procedure of some primary function blocks are presented, with the simulation by Hspice. Finally, a typical application circuit is introduced, based on which the whole chip simulation is achieved.The higher efficiency is one of the most important design guidelines for DC-DC switching regulators, all the time. In this thesis a contracted circuit design style is introduced, that insures the converter obtains the higher efficiency and the industry's high power density with the circuit functions fully achieved.The design is implemented base on the 0.35um BCD technology, with the fully system-level simulations. The results indicate that the controller has a wide input voltage range with dynamic output voltage positioning, up to 96% conversion efficiency. .