A Boost White LED Driver with an On-Chip Compensator
A monolithic peak-current-mode boost WLED driver with an on-chip compensator is presented. In order to predict the system performance, the equivalent circuit model of boost WLED driver is constructed to obtain the system transfer function. Then, an on-chip compensator, which requires small layout area, is analyzed and designed. The simulation results, based on CSMC 0.5µm 40V BCD technology, show that the internal compensation technique provides high loop accuracy and stability over a wide load range from 20mA to 180mA. The proposed driver is capable of driving 10WLEDs connected in series or 3WLEDs with 9 strings in parallel. Protection circuits, such as over voltage protection (OVP), over temperature protection (OTP), over current protection (OCP) and under voltage lockout (UVLO) are also utilized to guarantee the safe operations of the system.
F. Zhou and L. N. He, "A Boost White LED Driver with an On-Chip Compensator", Advanced Materials Research, Vols. 588-589, pp. 798-801, 2012