Design And Implementation Of High Voltage And High Current Linear Regulator

With the rapid development of integrated circuits,the design and research of power management chips have received more and more attention.As an important part of the power management chip,the linear regulator has many advantages.However,due to the narrow input voltage range,some applications are limited.Most linear regulators with a typical input voltage range will collapse when the supply voltage is above 5V.In addition,traditional linear regulators have very low output currents,while high-performance FPGA,microprocessors or sensitive communication power supplies require large current linear regulators.In this context,this paper designed a high-voltage and high-current linear regulator with a voltage range of 5.5V~80V and a load current of 2A.In order to reduce the power consumption of the linear regulator,a pre-regulated circuit module is added to convert the input high voltage into a low voltage,which is used for a low voltage module such as a bandgap reference source,thereby avoiding the large power consumption generated by the high voltage power tube.The op amp of the bandgap reference module is frequency compensated by zero-pole cancellation,and the error amplifier module of the linear regulator uses Miller compensation.This reduces the ESR zero requirement and can generate an internal zero to improve the stability of the bandgap reference and error amplifier output.In the linear regulator,the compensation method combined with the feedforward capacitor is used.The difference between this method and Miller compensation is that two zero points are generated for compensating the regulating tube PMOS control module.In addition,if the temperature of the chip is high,it will cause the chip to age quickly or even permanently damage the chip.When designing a linear regulator,the addition of an overtemperature protection module provides protection for the system when the temperature threshold is exceeded.When the load of the circuit exceeds the current limit threshold,the overcurrent protection module can be turned off to turn off the negative feedback loop of the linear regulator;The addition of the soft-start module allows the linear regulator to be turned on smoothly,ensuring proper operation of the circuit.At the end of the paper,the flow,rules and methods of layout design are introduced to complete the drawing and post-imitation of the overall layout of the high-voltage and high-current linear regulator.The high voltage and high current linear regulator designed in this paper is based on the 0.18?m BCD process of high voltage resistant LDMOS.The high voltage and high current linear regulator designed and verified by Cadence Spectre software is simulated and verified.The simulation results show that the pre-regulation circuit can generate about 5.5V when the input voltage is 10V;The temperature coefficient of the bandgap reference source circuit is 14.2215ppm/°C in the range of-55°C~125°C;The overall circuit simulation results of the linear regulator show that when the voltage is 10 V and the output voltage is 5V,the leakage voltage is 480.9m V and 384.7m V at 2A and 10 m A,respectively.;The loop gain is 100 d B and 83.3d B at 2A and 10 m A,respectively,and the phase margin is 60° and 86.5°,respectively;Power supply rejection ratio is 94.6d B at low frequencies and 78 d B at 10 k Hz.In addition,the soft-start,over-current and over-temperature circuit modules can also work normally,ensuring that the linear regulator can be turned on smoothly,and that the system can work normally under over-temperature and over-current conditions.