High-power White LED Driver Circuit Study And System Design

Early 60 s of last century, Nick Holonyak, Jr. and two of his graduate students M.George Craford and Russell Dean Dupis together to make the world’s first one LED(Light Emitting Diode). So far, LED ’s have been more than 50 years. LED light source with respect to the traditional trend has unparalleled advantages. because LED has high light efficiency and low pollution, high reliability and low power consumption, long life and small size many other advantages of great potential to replace traditional light sources. Which has very real implications for LED research and applications.Power to drive the white LED chips require special design management to achieve in practice that a uniform of light emission luminance required to achieve and temperature effect and high discrete of light beads and other shortcomings required to overcome. According to the characteristic curve I-V of LED, when the voltage is changed, the drive current will fluctuate sharply nonlinear, and the brightness of the LED is effected by drive current, so the luminous efficiency is not so high. Design a high performance LED driver circuit is particularly important.Paper intends to design a 7W high power white LED driver circuit. Through analysis of each module driver IC circuit works, combined with knowledge of the circuit system, based on the control IC chip built includes AC input rectifier filter module, power conversion and control module and output rectifier filter module these three parts of the drive circuit. Also proposed the parameters required to achieve the ultimate indicator of drive circuit according to the actual lighting requirements, and follow these parameters indicators for each circuit module detailed circuit calculation, analysis and design. After completing the circuit schematic design, the use of Altium Designer software to perform PCB layout and secondary design. Eventually we produce a circuit board and load a load, then test performance of indicators of circuit boards. The result showes that the output current, output voltage, power factor, efficiency, line regulation and load regulation of drive circuit board reached the initial design requirements, better finished 7W high power LED driver design.