Browse > Article
http://dx.doi.org/10.6113/JPE.2012.12.5.715

Time-Delay Effects on DC Characteristics of Peak Current Controlled Power LED Drivers  

Jung, Young-Seok (Dept. of Mechanical & Automotive Eng., Pukyong National University)
Kim, Marn-Go (Dept. of Control & Instrumentation Eng., Pukyong National University)
Publication Information
Journal of Power Electronics / v.12, no.5, 2012 , pp. 715-722 More about this Journal
Abstract
New discrete time domain models for the peak current controlled (PCC) power LED drivers in continuous conduction mode include for the first time the effects of the time delay in the pulse-width-modulator. Realistic amounts of time delay are found to have significant effects on the average output LED current and on the critical inductor value at the boundary between the two conduction modes. Especially, the time delay can provide an accurate LED current for the PCC buck converter with a wide input voltage. The models can also predict the critical inductor value at the mode boundary as functions of the input voltage and the time delay. The overshoot of the peak inductor current due to the time delay results in the increase of the average output current and the reduction of the critical inductor value at the mode boundary in all converters. Experimental results are presented for the PCC buck LED driver with constant-frequency controller.
Keywords
Time-delay effect; Peak current control; Power LED drivers; Average output current; PWM DC to DC converters;
Citations & Related Records
연도 인용수 순위
  • Reference
1 H. van der Broeck, G. Sauerlander and M. Wendt, "Power drivers and control schemes for LEDs," in Proceedings of IEEE-APEC"07, pp. 1319-1325, 2007.
2 Seoul Semiconductor Co., LTD. "Z-power LED Series - Technical Datasheet for X4218X," http://www.acriche.com/kr/, 2009.
3 O. Ronat, P. Green and S. Ragona, "Accurate current control to drive high power LED strings," in Proceedings of IEEE-APEC"06, pp. 376-380, 2006.
4 I.-H. Oh, "An analysis of current accuracies in peak and hysteretic current controlled power LED drivers," in Proceedings of IEEE-APEC"08, pp. 572-577, 2008.
5 R. D. Middlebrook, "Topics in multi-loop regulators and current-mode programming," IEEE Trans. Power Electron., Vol. 2, No. 2, pp. 109-124, Apr. 1987.
6 G. C. Ioannnidis, G. Charokopos, P. Marabeas and S. N. Manias, "A mixed-mode PWM controller," International Journal of Electronics, Vol. 97, pp. 1423-1438, 2010.   DOI   ScienceOn
7 M.G. Kim and M. J. Youn, "A discrete time domain modeling and analysis of controlled series resonant converter," IEEE Trans. Ind. Electron., Vol. 38, pp. 32-40, Feb. 1991.   DOI   ScienceOn
8 F. C. Lee, R. P. Iwens, Y. Yu, and J. E. Triner, "Generalized computer-aided discrete-time modeling and analysis of dc-dc converters," IEEE Trans. Industr. Electron. Contr. Instrum., Vol. 26, pp. 58-69, May 1979.   DOI   ScienceOn
9 G.C. Verghese, M.E. Elbuluk, and J.G. Kassakian, "A general approach to sampled-data modeling for power electronic circuit," IEEE Trans. Power Electronics, Vol. 1, pp. 76-89, Apr. 1986.   DOI   ScienceOn
10 S. Cuk and R.D. Middlebrook, "A general unified approach to modeling switching DC-To-DC converters in discontinuous conduction mode," in Proceedings of IEEE-PESC"77, pp. 36-57, 1977.