【正文】 明：電路 不帶負(fù)載的 靜態(tài)電流為 uA， 系統(tǒng) 帶寬幾乎不隨負(fù)載變化，在輸出電流范圍內(nèi)能保證 較好 的 穩(wěn)定性。針對(duì)文中采用的兩級(jí)級(jí)聯(lián)誤差放大器直接驅(qū)動(dòng)調(diào)整管柵極的拓?fù)浣Y(jié)構(gòu)，引入嵌套式密勒補(bǔ)償和動(dòng)態(tài)零點(diǎn)補(bǔ)償 兩種 方法來保證系統(tǒng)的穩(wěn)定性要求。 本文首先簡(jiǎn)要介紹 了 LDO線性穩(wěn)壓器的工作原理與基本性能指標(biāo)。 I LDO線性穩(wěn)壓器設(shè)計(jì)畢業(yè)論文 摘 要 隨著電源管理 IC技術(shù)的不斷發(fā)展，高性能低成本的電源管理芯片越來越受 到用戶的 青睞。其次，從瞬態(tài)、直流、交流三方面對(duì)系統(tǒng)結(jié)構(gòu)進(jìn)行深入研究，闡述 LDO穩(wěn)壓器的設(shè)計(jì)要點(diǎn)與各種參數(shù)的折衷關(guān)系。 討論了嵌套式密勒補(bǔ)償中調(diào)零電阻可能存在的位置，確定最合適的補(bǔ)償結(jié)構(gòu)從而有效地消除了右半平面零點(diǎn)對(duì)系統(tǒng)穩(wěn)定性的影響。 關(guān)鍵詞： 線性穩(wěn)壓器 ， 低壓差 ， 嵌套式密勒補(bǔ)償 ， 動(dòng)態(tài)零點(diǎn)補(bǔ)償 ， 低功耗 II Abstract With rapid development of power IC technology, high performance low cost power management chips bee more and more popular. LDO linear regulator is widely used in various kinds of DC regulating voltage circuits, for the benefits of low noise, high power supply rejection ratio (PSRR), micro power loss, and simple peripheral structure etc. In order to meet the needs of power market development, bining with self features of LDO system, this thesis proposes a kind of LDO linear regulator with low power and excellent stability. Firstly, this thesis gives a brief introduction on working principles and basic indicators of LDO regulator. System structure will be deeply discussed in TRAN, DC, AC three aspects and designing key points along with various parameter tradeoff relationships will be expounded subsequently. Then, optimums every submodule and determines the final system architecture from the angle of low power design. In order to obtain the path to research on stability of LDO system, calculates loop gain and deduces zeropole distribution by setting up AC small signal models. Nested miller pensation (NMC) and Trackingfrequency pensation will be introduced to ensure the stability of LDO topological structure which adopts two stage cascade error amplifier driving pass element directly. Discusses probable situation of nulling resistor in NMC circuits, and eliminates effect of righthalfplane zero effectively by fixing a best pensation structure. Analyzes structure and working principle of every submodule in detail, simulation results of whole chip will be shown in the end. Circuit design is based on CSMC CMOS process and simulation has been pleted under different binations of spice models, supply voltages and operating temperatures. The whole chip cost static current of , bandwidth is almost constant and the system keep excellent stability under whole output current range. III Keywords ： Linear Regulator Low Dropout Voltage Nested Miller Compensation Trackingfrequency Compensation Low Power IV 目 錄 摘 要 ..........................................................................................................(I) Abstract ...................................................................................................... (II) 1 緒論 LDO 線性穩(wěn)壓器的研究意義 ........................................................... (1) LDO 線性穩(wěn)壓器的研究目的 ........................................................... (4) 論文章節(jié)安排 ..................................................................................... (4) 2 LDO 線性穩(wěn)壓器的簡(jiǎn)介 LDO 的結(jié)構(gòu)與工作原理 ................................................................... (6) LDO 的基本性能指標(biāo) ....................................................................... (7) LDO 的基本應(yīng)用 .............................................................................. (10) 本章小結(jié) ........................................................................................... (12) 3 LDO 系統(tǒng)架構(gòu)的設(shè)計(jì)考慮 LDO 系統(tǒng)電路的瞬態(tài)研究 ............................................................. (13) LDO 系統(tǒng)電路的直流研究 ............................................................. (16) LDO 系統(tǒng)電路的交流研究 ............................................................. (17) LDO 子模塊的設(shè)計(jì)考慮 ................................................................. (19) 本章小結(jié) ........................................................................................... (25) 4 LDO 穩(wěn)定性研究與補(bǔ)償方式的確定 LDO 環(huán)路增益的建模 ..................................................................... (27) 傳統(tǒng) ESR 電阻補(bǔ)償 ......................................................................... (29) LDO 補(bǔ)償方式的優(yōu)化 ..................................................................... (34) 本章小結(jié) ........................................................................................... (43) 5 模塊電路的實(shí)現(xiàn)與仿真 基準(zhǔn)與偏置電路的設(shè)計(jì) ................................................................... (44) V 恒定限流電路的設(shè)計(jì) ....................................................................... (47) FOLDBACK 電路的設(shè)計(jì) ................................................................ (50) 本章小結(jié) ........................................................................................... (54) 6 LDO 整體電路仿真與分析 瞬態(tài)仿真與分析 ............................................................................... (55) 直流仿真與分析 ............................................................................... (56) 交流仿真與分析 ............................................................................... (58) 本章小結(jié) ........................................................................................... (59) 7 全文總結(jié) ............................................................................................. (61) 致 謝 ................................................................................................... (63) 參考文獻(xiàn) ................................................................................................... (64) 1 1 緒 論 半導(dǎo)體工藝技術(shù)的提高及便攜式電子產(chǎn)品的普及促使電源管理 IC有了長(zhǎng)足的發(fā)展。隨著半導(dǎo)體技術(shù)的飛速發(fā)展，電源管理 技術(shù)也 在 不斷進(jìn)步。 過去 電源管理 IC供應(yīng)一直將關(guān)注重點(diǎn)放在管理功率的傳遞上，即如何為不同的負(fù)載器件分 配不同的功率。美國(guó)國(guó)家半導(dǎo)體公司的自適應(yīng)電壓調(diào)整 (AVS)技術(shù)和 TI的動(dòng)態(tài)電壓與頻率調(diào)整 (DVFS)技術(shù)就是為了滿足這一功率管理挑戰(zhàn)而提出的解決辦法。隨著全球制造業(yè)進(jìn)一步向中國(guó)的轉(zhuǎn)移，預(yù)計(jì)到 2020年，中國(guó)將成為世界 上 最大的電源芯片需求市場(chǎng)，銷售額預(yù)計(jì)將達(dá)到 735億元人民幣。近年來，筆記本 電腦 、數(shù)碼相機(jī)和其它 IT產(chǎn)品的生產(chǎn)基地大規(guī)模向中國(guó)轉(zhuǎn)移，中國(guó)已經(jīng)成為世界 IT產(chǎn)品的生產(chǎn)基地；加之 “ 十一五 ” 規(guī)劃已經(jīng)明確要加快集成電路、軟件、關(guān)鍵元器件等重點(diǎn)產(chǎn)業(yè)的發(fā)展，未來 有 利于集成電路產(chǎn)業(yè)發(fā)展的政策還將繼續(xù)推出 ； 2）下游制造市場(chǎng)的拉動(dòng)。一般認(rèn)為線性穩(wěn)壓電