An adjustable brightness LED driver with high efficiency, high stability and low power consumption

An adjustable brightness LED driver with high efficiency, high stability and low power consumption is proposed. In order to obtain high stability at different working conditions, a novel voltage loop adaptive frequency compensation circuit is constructed. Moreover, the high efficiency of this system is realized by using the LDO power supply derived from the systems output, which reduces the system's power consumption. The different light intensities are obtained by setting the maximum of the LED load current. The LED driver is designed on a 0.18μm process with an input voltage range of 5V- 35V. Meanwhile, the working frequency is adjustable and synchronized with the external clock. The simulation results demonstrate that the LED driver is a single polar system through the adaptive frequency compensation circuit and eliminating the effect of zero-pole pair.