System Analysis And Design Of Buck PWM DC/DC Converter

This thesis discusses the fundamental of a buck DC-DC converter. According to the strict request for the bulk, cost and power, the architecture of the system is designed.The following is the main characteristics of the converter: PWM control mode improves the noise and EMI performance of power supply ic;Advanced Current Mode circuit are specially used to ensure better supply & load line regulation and better transient response,more easyer compensation net and better stability ,and less fluctuate of output voltage;using the BCD05 technology of JAZZ company make the resistance of switch MOSFET less than the traditional one,improves efficiency of the power supply;With high frequency of switch,SMT (Surface mounting technology) capacitor & inductor can be applied to minimize the bulk of the power supply system.This thesis has given a new method of selecting compensation network. Use simple formula for calculating compensation reached the network element specific parameters. To ensure that the different output filter capacitor and load cases, the power system remains stable.Simulate all critical functional blocks and give results with Spectre. Select different components, simulate the system and give the results about system characters. The result showed the efficiency at the variable loads. In the voltage range of input 4.75V-15V and output 1.235V-13V, the converter can be reached 2A of output current, and maintain system stability. Switching frequency is 400KHZ, maximum duty cycle is 90%.The maximum efficiency is over 95%.