Multiplexed Output DC/DC Power Module Design And Implementation

As the number of electronic device inside the spacecraft becomes more and more, thenumber of the supply voltage which is requested to supply by aviation secondary electricsource is also increasing and the voltage is lower, at the same time greater demands are beingplaced on each path of output voltage ripple and dynamic characteristics. In orderto provide DC power to the auxiliary equipment of a certain type of aircraft, this topic isexpected to develop a DC/DC power module which has a 28 V rated input and four ways ofoutput.First of all, through the consult massive material this paper analyzes the developmenttrend of the high frequency switch power supply at home and abroad, studies the topologicalstructure of multi output switching power supply, analyzes and compares the isolationtype low power DC/DC converter circuit topology, and determines to use fly-back converteras the main circuit topology, then the overall scheme of the system is determined.Secondly, the paper designs each module of circuit, around thePWM controller LM5001 and high-frequency transformer as the core, by using theinput circuit, the control chip peripheral circuit, feedback circuit, the output filter circuitthese module circuits achieves the main circuit output stably. And the article describes theuse of area product(AP) method to confirm the core model of the high frequencytransformer, and the steps of selecting the primary and secondary windings parameters.Through the step-down design of the main circuit, stabilizes the output of other three roads.Finally the whole circuit schematic is given through the reasonable choice of topology,circuit and design parameters.Thirdly, based on the realization of a stable output, using a buck LMZ10501 nano-module carries out twice to transform the output voltage and realizes function ofthe other three outputs. On the basis of the schematic circuit diagram, the paper describes thewiring rules of PCB of switching power supply, and makes PCB circuit.Finally, based on theoretical analysis and circuit design, make the powersupply prototype and test the main technical indexes. The overall test results of the prototypeshow that every indicator meets the design requirements and the power supply has the stableoutput voltage.