Adaptive Zero Compensation Of Low Pressure Drop Of The Power Supply Regulator Design

Low dropout regulator (LDO) with high performance such as high power efficiency, high power-supply rejection ratio (PSRR) and high accuracy is presented in this thesis. This paper begins with introduction the newest configuration and zero compensation to improve the stability for the system, after presenting the drawbacks, a new kind zero compensation is brought forward—self-adaption zero compensation to improve performance of LDO. The nulling resistor zero compensation using adjustable resistor in two stage error amplifier is adopted in LDO circuit.When designing the main circuit and auxiliary circuit, low current design is considered to improve the power efficiency. Auxiliary circuit such as bandgap, current bias circuit, over current protection circuit and over heat protection circuit provide the reliability and stability for chip function.As for simulation, specific performances such as AC and transient performance are simulated for LDO system. Simulation is also done for auxiliary circuit to insure right function and stability in closed system.LDO presented in this thesis has been taped out in hynix 0.5um 2P3M mixed signal CMOS technology. The test shows the right function and good performance such as high accuracy, high PSRR, low line regulation and load regulation, low static current, etc. The performance is compared to what in the newest configuration, which shows that the idea and new zero compensation is wonderful to improve and trade off performance.Self-adaption zero compensation presented in this thesis is proved right. The idea and circuit are practical and advantageous.