A Design of 0.18μm CMOS Low Dropout Linear Regulator for LED Driver Chip

LED is used widely in signal lamp, screen, and many other fields. This paper proposes a low dropout linear regulator (LDO) for LED driver chip. The designed LDO comprises a bandgap reference, an error amplifier using fold cascode technology and its biasing circuit. The supply voltage is from 5 V to 12V.Through the simulation of gpdk 180nm process model, the output voltage is stable 1.8V with maximum dropout voltage of 82mv at 10mA current load and the maximum current load of this LDO is about 46mA. The proposed LDO achieve about 62-degree phase margin and its DC PSR is -40 dB at 10mA current load. Its Load Regulation (LDR) is 57.56mV/A and its Line Regulation (LNR) is 11.72 mV/V at 10mA current load. The LDO has a temperature characteristic from -40°C to 125°C with about 22ppm/°C TC. As a result, the proposed LDO is suitable for LED driver chip.