This paper presents circuit techniques to improve the efficiency of high-current LED drivers. An error-averaged, senseFET-based current sensing technique is used to regulate the LED current accurately. Because the proposed scheme eliminates the series current-regulation element present in all conventional LED drivers, it greatly improves efficiency and reduces cost. The converter operates in three different operating modes, namely buck, buck-boost, and boost modes, and achieves high efficiency over the entire Li-Ion battery range (3-5.5 V). Fabricated in 0.5-μm CMOS process, the prototype occupies an active area of 5 mm