Modeling System Of Current-Mode-Controlled Boost Converter And Design Of The Controller

The switching power converters has become the primary control strategy in power supply due to it's small space, light weight, low power dissipation, high efficiency, adoption and broad applicability, etc. Boost converter is widely used in the high efficiency electrical portable products because it could be satisfied the demand of low input voltage, high output voltage and high power density. Considering these factors, a highly efficient current-mode Boost converter has been designed from the starting point of system-modeling.This thesis firstly studies the work and control principle of the Boost converter. The Continuous-Conduction-Mode and Pulse-Width-Modulation control of the Boost converter have been thoroughly analyzed. Secondly, the peak current mode controlled Boost converter is modeled base on power stage and control closed-loop. Small signal model of the system and closed-loop transfer functions of the system are obtained. Then, through thorough analysis and design the parameter of the current loop and voltage loop, a system-level design of the converter is completed. Performance of the system-level design is validated with Matlab. Finally, the converter on circuit-level is designed based on the performance of system-level. Mainly studies the design of oscillator, error amplifier and PWM comparator block. Design performance of the sub-block and whole-chip are verified with Hspice.The circuit design is base on the 0.6μm BCD process. Hspice simulation results show that the performance of sub-block is conformed to the system-level, and the controller has 0.4% output ripple and 88% typical conversion efficiency.