Design And Research Of Two Kinds Phase Output Synchronous Rectification DC-DC BUCK Controller

As portable electronic equipment moves towards low-voltage low-power design,the scale of integration of CPU, MCU and other digital processors increase as well as the operating frequency,The requirement of power supply’ current is also growing, which requires the power supply system to provide high current and low voltage output capability.This task has designed a synchronous rectification BUCK DC-DC converter with two output channels,whose switching frequency can be selected(250KHz、400KHz、600KHz) or continuous frequency(140KHz-650KHz).The power conversion efficiency of heavy load conditon can reach above 90% with good line regulation and load regulation.With input voltage range of 4V-40 V and the output voltage range of 0.8V-10 V, the converter can provide large output current.Based on top-down design approach and combined with theoretical analysis,the paper clarify the overall structure of dual-channel converter architecture, and describe the advantages and disadvantages of using this architecture on the chip scale.The verification of the PWM loop control method make us to optimize the design and analysis of this optimization method loop compensation scheme. Above this, we designed some modules in the PWM loop, such as the error amplifier, PWM comparator, slope compensation circuits, oscillator, etc. Finally, the paper analyzes the structure and major peripheral devices and gives the simulation data for some parameters according to the overall system chip simulation data.Simulation results in the simulation conditions of the output voltage of 3.3V, output current of 5A and output voltage of 8.5V output current of 3.5A meet the design requirements.