A Novel Current Sensing Circuit for LED Driver ICs
Seok-In Hong, Jin-Wook Han, Oh‐Kyong Kwon · ICEIC : International Conference on Electronics, Informations and Communications · 2008
A novel current sensing circuit used in LED driver ICs is proposed using a sensFET technique to achieve the high accuracy, simple structure and lossless current sensing. The proposed current sensing circuit consists of enable switches for blocking the high voltage of drain node of power-MOS at the input terminal of op-amp, op-amp for the voltage mirror, sensFET, current mirror and sensing resistor to convert the current to the voltage. The proposed current sensing circuit and LED driver are designed and simulated using BCD 0.35 ㎛ technology. Simulation results show that the accuracy of the proposed current sensing circuit is higher than 96.5% in the Li-ion battery supply range.