A high precision low dropout regulator with nested feedback loops
A high precision low dropout regulator (LDO) with nested feedback loops is proposed in this paper. By nesting a zero-tracking compensation loop inside of the negative feedback loop comprising an error amplifier, the independence of off-chip capacitor and effective series resistance (ESR) is ensured for different load currents and operating voltages. This circuit is designed and fabricated using a 0.35 ? m standard CMOS process. The die area is a 1350 ? m  560 ? m . The measurement results show that the total error of the output voltage caused by line and load variations is less than 3% in low quiescent current (Iddq) or low voltage scenarios. Besides, the smallest dropout of the LDO, 0.11V, while the output current is 165mA, the output load is 4.7 ? F and 20 in parallel.
high precision low dropout ldo low noise