Design And Realization Of A High-Bandwidth And Low Output Regulator

In recent years,the emergence of large-scale system on chip（SoC）has made power management chips with excellent performance gradually become a hot spot in the field of analog circuit design.The low power consumption,low voltage and high stability requirements of electronic systems have made great progress in power management chips development.Among them,linear regulated power supplies are widely used in various low-voltage power supply systems due to their high power supply rejection ratio,low cost,output ripple-free,and high reliability.This paper studies and develops a linear regulated power supply chip based on the design principle and design index of linear regulated power supply.The chip has significant advantages such as fast transient response,5A load capacity and fast transient response ability.Components and working principles of the linear regulated power supply was first introduced,and introduced the system-level performance indicators and calculation methods in detail,and establishes a complete theoretical basis for the actual circuit compromise design below.This paper introduces the system-level architecture design of linear regulated power supply.The basic operational amplifier structure model is used to explain the Miller effect and the distribution of poles and poles in the loop.This paper introduced Three frequency compensation methods and proposed a kind of Improved Miller compensation method for frequency compensation.Then,a basic compensation model is used to explain the transient response principle.The influence of various system indicators on the transient response of the loop is introduced by the analysis method of the large and small signals.The optimization scheme adopted in this paper is given.Finally,the actual circuit design,simulation and test work were carried out.During the design process,a bandgap reference source with extremely low temperature drift was developed,and high-order temperature compensation technology was adopted to make the temperature drift coefficient as low as 1.7×10^-6/°C,and according to the design principle,the design ideas of other modules are introduced in detail.At the end of the design,the photo of the actual layout and the implementation of the key parts of the layout design are given.The fast transient response linear regulated power supply designed in this paper is based on a bipolar process and uses a large area array NPN transistor as the output adjustment tube.The chip has a 1.2V output voltage,5A current output,20MHz bandwidth,and is equipped with overheating and overcurrent protection.typical model simulation and three-temperature actual test results show that under the premise of load 10μF capacitor,this linear regulated power supply start within 10μs,the output load regulation rate is only0.15%,and the full load jump-up and down-shoot value is less than 15mV.The up-and-down stability time is less than 5μs,and the indicators meet the design requirements of the Ministry of Aerospace Industry.