Design Of A Boost Switching Power Supply

The power supply is not only an indispensable part of all electronic equipmentalso is the drive source of various functions，and it’s quality direct impact on theexcellent performance of the electronic equipment. It can be divided into linearpower, Phase-controlled power and switch power supply which according to thedifferences of structure and principle. It is due to the small size, light weight, highefficiency advantages,the great attention has been devoted to the research ofSwitching power supply, with the continuous improvement of microelectronicstechnology, different kinds of forms have been widely used in computer, electroniccommunication equipment and various kind of instruments.In this thesis, on the basis of a detailed analysis of various power structure andworking principle, it analyses the main technical characteristics of the switch powersupply in the output voltage, efficiency, volume, weight and the ripple.Using theTOP245YN for switching power control module and PWM modulation method,design to complete a fly-back high-frequency switching power supply. it can completefront-end output of the pre-regulator with use of the Digital Potentiometer DS3502.As D/A output control port，the one-chip computer C8051F120SCM DA0tube feethas12bit resolution rate, which makes the output control precision can reach1V,namely single chip every digital quantity can control the voltage of0.2mV. ItRealize the switch power supply voltage in linear range of accurate output, andfurther reduce output loss in low voltage current in MOS pipe.After design of the circuit simulation, that has completed the physical productionof switch power supply, and apply it to the LED performance parameters tester, theactual operation results show that the switch power supply output voltage DC for36V,ripple coefficient for±1%, efficiency for82%. Through the single-chipmicrocomputer control, the voltage linear range voltage can be continuouslyadjustable between0V~36V. Finally, a error analysis on the various parametersobtained in the test meets design requirements, satisfy of system the actual need ofwork.The innovation of this paper lie in the combination of high-frequency switching power supplies and linear power supplies which including the advantages of them,improve efficiency, the load capacity and the accuracy of linear output voltage.