Design Of Low Dropout Linear Regulator Based On High Temperature Process

High temperature electronic devices are widely used in oil and gas exploration,and the demand for aeronautical equipment and vehicle-borne equipment is becoming increasingly prominent.The products are mainly used in vehicle-borne(engine,brake system,engine),aerospace and space applications(rocket detector,manned spaceflight)and other applications.In high temperature signal acquisition system,high temperature linear regulator has a wide application demand.In the field of manned spaceflight and rocket detection,the processing of high temperature sensor data of rocket and engine control system of power system are potential application scenarios of high temperature devices to solve the problem of high temperature reliability of control system.Based on XFAB’s high temperature process XA035 for automotive electronic applications,a low-dropout linear regulator with high stability and 200 mA load current is designed by using Cadence tool.Its input voltage range is 5.5V~30V,output is fixed 5V,working temperature range is-55 C~175 C,supporting current limiting,over-voltage and over-temperature protection functions.The circuit is mainly composed of reference voltage VREF,error amplifier EA,power transistor,voltage dividing resistor,over-temperature protection OTP,over-voltage protection OVP,current limiting protection OCP and so on.Firstly,the basic principle and performance parameters of low-drop linear regulator are studied,and the design rules of high-temperature CMOS circuit are studied,and the hightemperature process is introduced and selected.In this thesis,the temperature resistance of 175 C is achieved by high-temperature process combined with high-temperature circuit design and layout optimization,and the modules of low-drop linear regulator circuit are given.The stability and transient response of the low-drop linear regulator are studied and analyzed.The buffer stage and follow-up zero compensation structure are used to compensate the load current to ensure the stability of the loop.The loop BUFFER is used to design the transient response of the lifting circuit.This thesis uses Cadence Spectre software to simulate and analyze the performance parameters of the high temperature and low voltage differential linear regulator designed in this thesis.The simulation results show that the output voltage stability error of the low-drop Linear Regulator designed in this thesis is controlled within 3% of the output voltage temperature drift coefficient within the operating temperature range of-55 ~175 C.The PSRR of the circuit is still greater than 50 dB at the low frequency of 64 dB and the frequency of 1 KHz.The phase margin is sufficient and the system is stable.The protection modules work normally,and the performance parameters meet the design objectives.Finally,this thesis studies the difficulties and matters needing attention in the layout design of high temperature circuit and completes the layout drawing of the high temperature and low voltage differential linear regulator designed in this thesis.Finally,this thesis studies the matters needing attention in the layout design of high temperature circuit and completes the layout drawing of high temperature low-dropout voltage regulator.