DC-DC Switching Power Supply Based On Digital Control Algorithm Design

With the development of power electronic technology, switching power supply is becoming more and more significant in the role of circuit design. By controlling the switching power supply transistor conduction time and closing time length, to maintain the stability of the output voltage. Generally, switching power supply with pulse frequency modulation (PWM) control of IC chips and MOS transistor. So far, the power electronic technology has made significant progress, made switch power supply and constant innovation. The characteristics of the switch power supply of small volume, the high efficiency has become the main force of the power market. Is the rapid development of electronic information industry required a high precision of power supply.This study focuses on an algorithm design of switching power supply, this kind of algorithm describes when the switching power supply works in fixed frequency on discrete time model, the model of the buck converter is designed based on the discrete time model, the closed loop of switching power supply includes an A/D converter, A pulse width modulator, A compensator circuit and voltage conversion module, this model is different from other models is that all of these modules are directly in the Z-domain modeling design. Relative to continuous time model design, the circuit is different in the design of error, the s-z transformation error is the main difference, and the design of the main error source, switching power supply in the s domain can exceed the key compared to the design of continuous time, the instances of this article is based on the discrete time model design, by designing a closed-loop control structure of the circuit to realize accurate control of switching power supply output, the design process is firstly designed by Matlab simulation, it proves the correctness of the design in the model validation. Secondly, through the research of the structure of the controller, we can achieve the best proportion of controller in power consumption and delay, it is concluded that the basic framework of the controller, through the Verilog language coding structure of controller, the controller structure eventually write into FPGA, finally in Simetrix software, join the actual effect of circuit components, such as inductance additional resistors, capacitors, additional resistance and so on, the simulation results verify the correctness of the algorithm design.