The Design Of A Low Quiescent Current LDO Base On The0.18μm CMOS Technology

The voltage control is the most basic function of the electronic system,stable voltage is necessary for the normal work of the electronic system. Theprogress of the integrated circuit technology has made today’s electronicproducts, such as mobile phone, tablet computer to the direction of more portable,lower power consumption. These advances also put forward higher requirementsfor the technology of power management. As the important part of power supplymanagement technology, low-dropout voltage linear regulators technology hassome characteristic, such as low noise, low cost, and simpl e structure, so it iswidely used in the electronic equipment. Therefore, design a low-dropout voltageregulator with good index is of great importance.This paper, based on the0.18m CMOS technology, design a typicallow-dropout voltage linear regulator, the output voltage is stable at3.3v; theinput voltage range of3.3v-4.2v; and it has low quiescent current; Together withhigh power rejection ratio and good noise performance, this low-dropout voltagelinear regulator is suitable for electronic equipment with higher demand in powersupply quality. The simulation results show that under all the technologicalcorner, Temperature drift voltage is9mV; when load current is10m A, drop-outvoltage is113mV; linear adjust rate less than%1;when the load capacitance is1Pf and frequency less often than100KHZ, Power Supply Rejection Ratio morethan the60dB; when the load current is20mA, the phase margin is about70°;when the temperature between45℃and125℃, the static current is more than30A and less than45A.This paper first introduced the effect and the development status of thevoltage regulator in power management technology; secondly introduced thebasic working principle, structure and the meanings of the main parameters ofthe LDO; then do some theoretical analysis of the LDO, introduce therelationships of Components parameters and design parameter in the circuit;discussed the circuit structure and its characteristics that can be used in eachparts of LDO in detail, analyzed each influencing factor of LDO performance,and carry on the detailed introduction; then ensure the circuit and its parametersaccording to the design demand, use hspice simulation software to coordinateand give the simulation results; finally, sum up this course design and expoundthe advantages and disadvantages of the whole design.