Design of 1W LED drive array with single-group dimmer
LIU Qi, QIN Huibin, ZHANG Zhenyin
(School of Electronic and Information, Hangzhou Dianzi University, Hangzhou 310018, China)
Abstract: In  order to solve the problem that the multiple LED driver of constant voltage easily damage chips, the LED driver of multiple constant current source supplied by a single voltage source supply was proposed. The efficiency of the dimming circuit of the two constant current sources was improved. In order to achieve constant output, Maxim′s MAX668, based on the controller of the Boost topology, was adopted by the constant voltage source. The multiresonant selfexcited oscillator consisted by NE555 was used to generate a fixed frequency and produce adjustable duty cycle pulse width modulation(PWM) output. Maxim′s MAX16803 and SIEN′s SN3350 were respectively used as the constant current sources. When loading the PWM input, single dimming was achieved and constant current output was attained. The results show that this research paves the way for the further production of highefficiency and highpower LED driver array with single dimmer.
Key words: highpower LED; constant voltage source; constant current source;pulse width modulation(PWM) dimming