The Design Of High-PSRR And Low-power LDO

With the development ofintegrated circuit industry and the semiconductor technology,power management technology arouse wide attention of power supply management market.Based on the research of the power management technology,the use of a variety of methods to reduce the power consumption,enables portable devices to run under the condition of limited battery capacity longer and work more stable.Low dropout linear regulators occupy the important position in power management marketfor its low noise,low cost,high performance and the advantages of the less peripheral devices.It is widely used in automotive electronic products,portable electronic devices,communications equipment and industrial and medical equipment field.Due to the requirement of humanized design demand of portable electronic productsis higher,power consumption,standby time and so on.,go deep into the power supply design is necessary to reduce the PCB road area,improve power supply rejection ratio,power supply circuit is not using inductance and need to have the ability of instantaneous proofreading and output state self-checking function,circuit of low cost,the schematic is easy to design,from what has been discussed above,low dropout linear regulators is the most reasonable choice.Therefore the most rational and highly cost effectivechoice is the low dropout linear regulators.In this paper,LDO is discussed and studied to achieve high power supply ripple rejection ratio andlow powerconsumption.In this paper,a low dropout linear regulator with high PSRR and low power consumption is designed.Based on the TSMC28nm process,There are mainly two parts,Bandgap reference is the foundation of all regulators.It has advantages of simple construction、low-power consumption、high PSRR and low temperature coefficient.It’s the indispensable of analog integrated circuit,and relative to system quality.An excellent bandgap reference is the headstone of a good LDO.bandgap reference source of power consumption is lower than 2.5 mA,temperature drift less than 30ppm,PSRR reach 70 dB.Low dropout linear voltage regulator output voltage from 1.2 V to 0.9 V,It’s fully considered the realization of the low power consumption,finally in addition to the bandgap reference module,static power within 100 μA,PSRR reaches as high as possible,at least 70 dB.The working principle and various performance indexes of low dropout linear regulator are discussed,such as bandgap reference、pass element、error amplifier、feedback and so on.focus on the analysis of the low power consumption and high PSRR implementation issues.Then according to the parameters to designcircuit,in the meantime making simulation of circuit and doing the layout design.The design of this paper is based on the 28nm process of TSMC,the matters need attention in the design of circuit and layout are detailed introducted in this paper.The results show that the design of circuit satisfied the basic indicators.