SAR-Controlled Adaptive Off-Time Technique Without Sensing Resistor for Achieving High Efficiency and Accuracy LED Lighting System. - Chao-Hsuan Liu; Chun-Yu Hsieh; Yu-Chiao Hsieh; Ting-Jung Tai; Ke-Horng Chen (IEEE Trans. Circuits Syst. I Regul. Pap., 2010)