Research And Design Of A LDO XD1409with Low Dropout Voltage And Stability

A 600 m A, stability and low-dropout LDO converter XD1409 is designed in this thesis,which can be integrated in the on-chip system, and it is widely used in fast response,low power consumption of portable devices such as mobile phones, wireless modem,and personal digital assistant(PDA).In the 20 th century, the integrated circuit technology and microelectronic technology obtained the swift development, and the industrial chain was formed in the 1970 s. The progress of semiconductor technology has made the integrated circuit be widely used in all areas of the national economy and society which has become the important factors influencing economic development and national security. Battery powered and handheld applications require power management techniques to extend the life of the battery and the opreation life of the device. Power manager is responsible for providing energy to the subsystem in the system. These subsystems need a analog voltage with low leakage voltage, good stability, low noise. Linear regulators can do this. Each LDO regulator demands a large exeternal capacitor,in the range of a few microfarads to performed level.With the continuous development of science and technology, such as mobile phones,laptops and other portable devices require a different voltage for different modules in power supply, so the on-chip system has been widely used in recent years. The power management chip occupying the important status with the output voltage of high precision, simple structure, low consumption, low noise linear voltage regulator.Therefore, it is necessary to study the linear regulators in the on-chip system.This paper introduces the background and development in power management, and then analyzes the classification of the power transformation technology, and introduces the power transformation technology used in the application of today’s portable electronic devices. And then analyzes the basic principle and steady state operating mode of low voltage linear voltage regulator circuit, and analyzes and discusses the stability of low voltage linear voltage regulator circuit. On this basis, the paper introduces various important performance parameters of linear regulator. According to the chip application environment and market demand. This paper developes the system function and specifications, and analyzes the chip of the overall system, determines the chip circuit module, and then introduces the typical application and peripheral devices of chip circuits. And describes the working principle of system-level chip and the key sub-block, such as reference voltage circuit, undervoltage lockout circuit, an error amplifier circuit, overcurrent protection circuit in detail.Based on a process of 0.8μm 5V Bi CMOS,the chip is designed and simulated with Cadence and Hspice.The simulation results show that the LDO input voltage is 5V,the output voltage is 1.8V,the max output current is 600 m A.The PSRR of lk Hz is 75.98 d B,line regulation is 0.016%/m V, load regulation is 0.02%/m A.The simulation results of whole chip show that XD1409 complete the design goal of low voltage, low quiescent current, good stability and high power supply rejection ratio.