Reasearch And Design Of Boost DC-DC Switching Power Supply

With the rapid development of the Internet and wireless communication technology,the demand of portable devices and personal consumer electronic products is incresing and which need power management chips for power conversion.As a kind of power management chip,switching power supply has wider application and higher performance requirements.On the basis of the analysis of the basic structure and principle of the switching power supply,a boost DC-DC switching power supply is designed in this thesis,it includs the following contents:Firstly,the basic structure,modulation mode and feedback control mode of the switching power supply are analyzed in this thesis.In order to improve the stability of the current loop of DC-DC switching power supply,two compensation circuits,which includs constant slope compensation circuit and adaptive slope compensation circuit are designed in this thesis.The constant slope compensation circuit is possible over compensation phenomenon,and which affects the transient response speed and load capacity of the system.The adaptive slope compensation circuit makes full use of its linear relationship between input and output voltage,inder to avoid over compensation phenomenon.Secondly,funcitional modules of the DC-DC switching power supply,which including the bandgap reference circuit,error amplifier circuit,oscillator circuit,PWM comparator circuit,adder circuit,V-I-V circuit,logic control circuit are designed in HHNEC 0.35?m BCD process.The bandgap reference circuit provides a high performance bias voltage for the system.The PWM comparator circuit produces a clock control signal with a period of 1MHz.The logic control circuit can generate the dead time and avoid the simultaneous conduction of the power MOS tube and the freewheeling MOS tube.Simulation results show that these functional modules meet the design requirements of DC-DC switching power supply.Finally,based on the designed functional module designed in this thesis,a boost DC-DC switching power supply is designed in HHNEC 0.35?m BCD process.Simulation results show that of the DC-DC switching power supply achieves the normal input voltage range from 3.7V to 4.2V,the output voltage of 9V,the output voltage ripple of 65 mV,the output voltage error rate of 0.36%,the maximum load current of 0.4A and the starting time of the converter of 100?s,the normal operating frequency is 1MHz and the conversion efficiency of 85.4%,The DC-DC switching power supply achieves well performance of linear transient adjustment rate and load transient adjustment rate.