一种低功耗快速瞬态响应无片外电容LDO  

A output-capacitorless LDO with fast transient response and low power

作　　者：於汉 张涛[1] YU Han;ZHANG Tao(School of Information Science and Engineering,Wuhan University of Science and Technology,Wuhan430081,China)

机构地区：[1]武汉科技大学信息科学与工程学院,湖北武汉430081

出　　处：《电子元件与材料》2024年第6期713-720,共8页Electronic Components And Materials

基　　金：国家自然科学基金(61873196)。

摘　　要：针对无片外电容LDO瞬态响应问题,提出了一种基于Miller BICMOS OTA结构的N型功率管LDO。BJT Push-Pull作为电路的中间级,具有低功耗、高增益、高摆率的特点。输出扰动通过电容耦合至中间级,形成了一条快速反馈环路,拓展了反馈环路带宽,提高了负载瞬态响应速度。因为输出级为源随器,系统整体为两级运放结构,仅需通过密勒电容进行补偿,就可以获得良好的稳定性。电路基于Hynix 180 nm BCD工艺设计,仿真结果显示,系统静态电流约为10μA,增益约为102 dB,带宽约为800 kHz,相位裕度约为61°,其中反馈环路带宽约为30 MHz。当输入电压为5 V,不接片外电容,负载电容为5 pF,输出电流从20 mA切换到200μA用时300 ps时,系统响应时间约为420 ps,过冲电压约为253 mV。In order to solve the problem of transient response of LDO without off-chip capacitance,an N-type power FET LDO based on Miller BICMOS OTA structure was proposed.As the intermediate stage of the circuit,BJT Push-Pull has the characteristics of low power consumption,high gain and high slew rate.The output disturbance was coupled to the intermediate stage through the capacitor,a fast feedback loop was formed,the bandwidth of the feedback loop was expanded and the load transient response speed was improved.Because the output stage is a source follower and the overall system is a two-stage op amp structure,good stability can be achieved just through the compensation of the Miller capacitor.The circuit was designed based on the Hynix 180 nm BCD process.The simulation results show that the quiescent current of the system is about 10μA,the gain is about 102 dB,the bandwidth is about 800 kHz,and the phase margin is about 61°.The feedback loop bandwidth is about 30 MHz.When the input voltage is 5 V,no external capacitor is connected,the load capacitance is 5 pF,and the output current switches from 20 mA to 200μA in 300 ps,the system response time is about 420 ps,and the overshoot voltage is about 253 mV.

关 键 词：NMOS BICMOS OTA BJT Push-Pull 前馈电容 

分 类 号：TN433[电子电信—微电子学与固体电子学]