| Light-emitting diode (Light Emitting Diode, LED) appeared in the later20thcentury as a new lighting source. LED play an important part in energy saving andenvironmental protection. As the LED can`t be directly powered by the power grid, sothe LED driver become an important research topic. LED driver which based on thedesign of switching power supply technology in engineering applications showed strongcompetitiveness. Through the study that programmable devices as LED driver circuitcore switching signal generator, can better meet the high level of integrat ion, simpleperipheral circuits and digital control.This article mainly talk about the relationship between the programmable devicesof C51series microcontrollers and LED driver, to study the programmable devicemicrocontroller as pulse width modulation (PWM) signal generator of LED driver andthe method of digitize control used in post-feedback system. Expounding the principlesand techniques of microcontroller hardware circuitry and LED driver, describing themethod of how to implement the software to change the pulse width modulated signal toadjust the drive power and mixed operation of the digital-to-analog circuit. Analyzingthe LED driver design requirements and safety regulation standards, giving the specificmethod of building power hardware circuit and Single Chip Microcomputer(SCM)minimum system circuit, designing the software control method based on SCM,completing high-power LED driver design based on SCM as PWM signal generator.Programmable device microcontroller technology LED driver system tests showthat,the correct design of the main power circuit structure and the right samplingfeedback circuit, can reasonable control of the duty cycle of the PWM signal andcomplete the reliable output of constant current and voltage on LED driver as well asenhance work efficiency. What is more it has the functions of scalable external interface.Finally it well achieve the purpose of the paper design requirements... |
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