Design of Buck LED Driver Circuits with Power Factor Correction

• Main Authors: Chih-Hung Wu, 吳至弘
• Other Authors: Tzuen-Lih Chern
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/36qre2

碩士 === 國立中山大學 === 電機工程學系研究所 === 97 === In the thesis, a LED driver circuit that is applied in low power LED lighting with constant output current and Power Factor Correction (PFC) is presented. For power stage of LED driver, a non-insulated switching Buck power converter without transformer is used, and develop equivalent mathematical model and block diagram of Buck converter while its inductor current operating in Continuous Conduction Mode(CCM). Furthermore, the closed loop PFC control circuit is designed by time-domain and frequency-domain analysis. In addition, because of the classical PFC control configuration needs the expensive multiplier, a LED driver circuit with PFC without multiplier is presented in this thesis in order to reduce the system cost and space of the circuit. Then, we confirm the designed circuit by simulation and experiment. By the results, the proposed system achieves constant output current control and power factor can reach to 0.92.