Design And Implementation Of 5A Low Dropout Voltage Power Supply

With the rapid development of semiconductor manufacturing technology,the chip market is becoming more mature,LDO power supply has continuously improved its position in power management IC.It plays an important role in the power chip market,which makes the power chip appear diverse and diversified.Compared with switching regulator power supply,it has the advantages of low noise,high power rejection ratio,simple peripheral circuit structure,stable output and so on.It has been widely used in the chip market.Therefore,according to the future development trend of power market and the characteristics of LDO power supply system,it is necessary to design fast transient response and output 5A current of LDO linear power supply to meet the needs of current market development.In the paper,the basic principle of LDO linear regulator power supply and the requirement of product design index and its typical application are introduced.Secondly,the small signal model of AC small signal is introduced,the loop gain of the system is constructed,and the open-loop gain and zero-pole position distribution of LDO circuit are deduced.In order to offset the poles of the loop to ensure the stability of the system,the capacitance equivalent series resistance compensation scheme,nested Miller compensation scheme and dynamic zero compensation scheme are studied,analyzed and compared in depth.Then the important parameters of LDO power supply are analyzed comprehensively to determine the LDO power supply.Design the final plan.Finally,the structure and working principle of each sub-module circuit are analyzed,and the simulation results of LDO power supply system module are given respectively.On this basis,the whole circuit simulation is carried out.The reliability analysis and design of product packaging and layout are also carried out under high current.In the paper,the circuit and layout are designed and simulated by Cadence software in 0.35 um CMOS process.The simulation results show that the circuit is a LDO linear power supply with low-dropout voltage of 500 m V,fast transient response function,maximum output of 5A and output of 2.5V.