【正文】 畢業(yè)設(shè)計(jì)（論文） 設(shè)計(jì)（論文）題目： LDO 誤差放大器頻率技術(shù)分析與設(shè)計(jì) 重慶郵電大學(xué)本科畢業(yè)設(shè)計(jì)（論文） 1 摘 要 近年來， CMOS 工藝水平不斷進(jìn)步，便攜式電子的應(yīng)用領(lǐng)域也不斷深入，使得低壓差線性穩(wěn)壓器 (LDO)的性能要求更加嚴(yán)格。 LDO 未來發(fā)展趨勢是：低成本、低噪聲、低功耗、高效率、高集成度、適用范圍更廣。國內(nèi) IC 行業(yè)起步較晚， LDO 的發(fā)展落后于先進(jìn)國際水平，主流電源芯片市場份額基本都被外國公司占據(jù)。因此，掌握基本電源技術(shù)知識，學(xué)習(xí)國際先進(jìn)水平，設(shè)計(jì)實(shí)用的新型結(jié)構(gòu)，對今后發(fā)展具有戰(zhàn)略性意義。 本文針對 LDO 的發(fā)展 要求，主要研究 LDO 的核心 —— 誤差放大器，且著重對誤差放大器頻率補(bǔ)償進(jìn)行分析和設(shè)計(jì)。結(jié)合國內(nèi)外現(xiàn)有三級放大器補(bǔ)償結(jié)構(gòu)的優(yōu)點(diǎn)，本論文采用單密勒電容前饋頻率補(bǔ)償 (SMFFC)，并用 Cadence 完成電路構(gòu)造和參數(shù)仿真。此放大器的設(shè)計(jì)采用 CSMC 工藝，在正負(fù)電源電壓分別為正負(fù)一伏，負(fù)載電容 120pF，負(fù)載電阻 25K 的情況下對電路進(jìn)行仿真，仿真達(dá)到指標(biāo)為：放大器的單位增益帶寬為 ,直流增益 ,相位裕度為 ，補(bǔ)償電容僅為， ，功耗僅為 。 分析與設(shè)計(jì)的具體內(nèi) 容有：第一章主要對 LDO 的工作原理和誤差放大器對 LDO 的影響進(jìn)行簡單的闡述，以引出下文對誤差放大器的分析。第二章一方面對誤差放大器基本電路單元進(jìn)行分析設(shè)計(jì)；另一方面著重分析放大器的頻率補(bǔ)償，運(yùn)用一種 SFMMC 結(jié)構(gòu)的補(bǔ)償方式，分析其小信號傳輸函數(shù)，確定零極點(diǎn)位置，實(shí)現(xiàn)了左半平面零點(diǎn)在頻率補(bǔ)償中的作用；第三章則根據(jù)本次設(shè)計(jì)提出的各項(xiàng)指標(biāo)對電流進(jìn)行分配從而計(jì)算出各管子的寬長比，并用 Candence仿真軟件對電路圖進(jìn)行仿真，分析仿真結(jié)果。從仿真結(jié)果可以看出，此誤差放大器達(dá)到了預(yù)期的補(bǔ)償目的，完成了設(shè)計(jì)指標(biāo)的要求。 文章結(jié)尾對本設(shè)計(jì)進(jìn)行了小結(jié) ,指出了設(shè)計(jì)中所存在的一些不足之處，并結(jié)合當(dāng)前設(shè)計(jì)和未來發(fā)展提出了進(jìn)一步的想法。 【關(guān)鍵詞】 低壓線性穩(wěn)壓器 誤差放大器 頻率補(bǔ)償 SMFFC 重慶郵電大學(xué)本科畢業(yè)設(shè)計(jì)（論文） 2 ABSTRACT In recent years, along with the continuous development of the process level and the deepening in the application fields of portable electronic equipments, the performance requirements of Low dropout Linear Regulator(LDO) is being more and more rigorous. The future development trends of LDO are: lower cost, lower noise, lower power consumption, higher efficiency, higher integration, and wider range of application. The domestic development of LDO is behind the advanced international standards, because the IC industry started late. And the market shares of power management chips are mainly occupied by foreign panies. Therefore, there is important strategic meaning to master the basic knowledge of power technology, study the international advanced skills, and design new circuit structures which are practical. Due to the requirement of LDO, this paper mainly study the core of LDO, namely, error amplifier, emphasizing on frequency pensation analysis and research. Based on the existing pensation structures of threestage error amplifier ,this paper introduces a kind of pensation called Single Miller Capacitor Feedforward Frequency Compensation(SMFFC). What’s more CSMC COMS technology is adopted, and circuits design and parametric simulation are acplished through the spectre simulation tool. The design of circuit is done here to drive a 120pF load. When the power supply voltage is 2V,the GBW achieves , the DC gain reaches to , the phase margin can be ,the miller capacitor is only ,and the power supply consumption is just . In chapter one, the basic construction and theory of LDO and the influence to LDO of error amplifier are interpreted in order to introduce the analysis of the error amplifier. In chapter two, on the one hand, the basic amplifier cells are studied and designed. On the another, the amplifier’s frequency pensation is analysized adopting a kind of SFMMC structure through analysizing its small signal transfer 重慶郵電大學(xué)本科畢業(yè)設(shè)計(jì)（論文） 3 function to confirm its locations of zeros and poles and achieve the purpose of frequency of frequency pensation through left halfplane zero. In chapter three, the current is attributed based on indictors of this design to calculate the rate of width and length of every transistor. .According to the simulation data, this design achieves the expected purpose of pensation, and pletes the requirements of design specifications. At the end of this paper, all the jobs are summarized briefly, while some existing disadvantages are pointed out. And the ideas concerning to this design and future development are also put forward. 【 Key words】 LDO。 Error Amplifier。 Single Miller Capacitor。 Frequency Compensation 重慶郵電大學(xué)本科畢業(yè)設(shè)計(jì)（論文） 4 目 錄 摘 要 ........................................................................................................................ 1 第一章 緒 論 .......................................................................................................... 5 第一節(jié) 研究背景及意義 ................................................................................. 5 第二節(jié) 國內(nèi)外研究現(xiàn)狀 ................................................................................. 6 第三節(jié) 本論文主要工作 ................................................................................. 8 第二章 低壓線性穩(wěn)壓器的介紹 .......................................................................... 10 第一節(jié) LDO 工作原理 .................................................................................... 10 第二節(jié) 誤差放大器對 LDO 的影響 ............................................................... 13 第三節(jié) 本章小結(jié) ........................................................................................... 14 第三章 誤差放大器電路分析與設(shè)計(jì) .................................................................. 15 第一節(jié) 基本電路單元設(shè)計(jì) ........................................................................... 15 第二節(jié) 頻率補(bǔ)償?shù)姆治雠c設(shè)計(jì) ................................................................... 19 第三節(jié) 本章小結(jié) ........................................................................................... 27 第四章 誤差放大器參數(shù)分析與仿真 .................................................................. 28 第一節(jié) 參數(shù)分析與計(jì)算 ............................................................................... 28 第二節(jié) 電路仿真 ........................................................................................... 31 第三節(jié) 本章小結(jié) ........................................................................................... 40 結(jié) 論 與 展 望 .................................................................................................... 41 致 謝 ...................................................................................................................... 43 參考文獻(xiàn) .................................................................................................................. 44 附 錄 ...........................