米勒補償是現今最被廣泛使用的頻率補償方法之一。其極點分離現象為雙級放大器供簡易而又可靠的穏定作用。可是，隨着亞微米 CMOS 技術及低電壓電路設計的興起，高增益同時又寬頻寬的放大器設計變得愈來愈困難。雖然多階段方式能實現高增益的放大器規格，但其頻寬會隨之縮窄，頻率補償亦會變得複雜及困難。 / 在過去，很多學術硏究報告都提出了不少方法去解決多階段放大器頻寬縮窄的問題，但這些方法往往離開複雜的頻率補償技巧及電路結構。為了根本性地解決此問題，本論文會提出一個虛擬雙階段放大器的設計。此放大器設計利用了兩個低增益階段來放大進入第二階段前的訊號振幅，從而放進整個放大器的頻寬及增益。由於其簡單的結構，這個設計仍然能夠採用穏定可靠的簡易米勒補償方式來穏定整個放大器。 / 這個設計由CMOS 180nm（互補式屬-氧化層-半導體180納米）技術製成。實驗結果證實了其高增益及寬頻寬的效能。另外，這果放大器亦同時應用在一個低通濾波器的實現上，用以證明其實際應用上的用途。實驗結果證實利用該放大器實現的低通濾波器比用一般雙段放大器的功率消耗減少近 45%。 / Miller compensation is one of the most widely adopted frequency compensation techniques for two-stage amplifier design. With its pole-splitting behavior achieved by connecting a capacitor between the output nodes of the two gain stages, Miller compensation provides a simple and reliable stabilizing function to two stage amplifiers. However, with the advance of sub-micron CMOS technology and low-voltage circuit designs, high-gain and wide-bandwidth amplifier design becomes more difficult. Although multi-stage amplifiers can be used to attain high-gain specification, the bandwidth will be degraded dramatically and the frequency compensation scheme becomes much more complicated. / To solve the problem, several researches have been done to improve the frequency response of multi-stage amplifiers so as to achieve high-gain and wide-bandwidth specifications simultaneously. However, these always result in the increase of circuit complexity and more complicated frequency compensation techniques. / In this thesis, a virtual two-stage Miller compensated amplifier will be proposed. By using two small gain stages, the characteristics of a conventional two-stage Miller compensated amplifier can be retained due to the low output impedance of the two gain stages. The small gain stages boost the input signal amplitude of the second stage such that the generated small-signal output current can be increased significantly. This results in wider signal bandwidth and higher voltage gain. / The proposed design has been fabricated in UMC CMOS 0.18μm technology. Experimental results have verified the concept. From the measurement, the unity-gain frequency of the proposed design is better than the conventional design by 4 times. Moreover, the voltage gain is improved by about 20dB. The current consumption is 124.76μA which is the nearly the same as the conventional design. / In order to show the improvement in real applications, the proposed amplifier has been applied to a fifth-order low-pass filter with corner frequency of 50kHz. Under the same performance, the power consumption of the filter using the proposed amplifier can be reduced by about 45%. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Poon, Hiu Ching. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references. / Abstracts also in Chinese. / Abstract --- p.i / Acknowledgments --- p.iv / Table of Content --- p.v / List of Figures --- p.vii / List of Tables --- p.xi / Symbols Declarations --- p.xii / Chapter Chapter 1 --- Background Information / Chapter 1.1 --- High-Gain Amplifier and its Application with Negative Feedback Configuration --- p.1-1 / Chapter 1.2 --- High-Gain Amplifier Design and the Tradeoffs --- p.1-6 / Chapter 1.3 --- High-Gain Amplifier Implementations --- p.1-8 / Chapter 1.4 --- Contribution and Outlines of the Thesis --- p.1-15 / References --- p.1-16 / Chapter Chapter 2 --- Analysis of Frequency Compensation Techniques / Chapter 2.1 --- Simple Miller Compensation --- p.2-1 / Chapter 2.2 --- Miller Compensation with Null Resistor --- p.2-10 / Chapter 2.3 --- Miller Compensation with Multipath Zero Cancellation --- p.2-13 / Chapter 2.4 --- Nested Miller Compensation --- p.2-15 / Chapter 2.5 --- Advanced Frequency Compensation Techniques --- p.2-17 / Chapter 2.6 --- Conclusion of Chapter --- p.2-20 / References --- p.2-22 / Chapter Chapter 3 --- Proposed Amplifier Design / Chapter 3.1 --- Gain Tolerance --- p.3-1 / Chapter 3.2 --- Adjustments on Simple Miller Compensated Two-Stage Amplifier --- p.3-3 / Chapter 3.3 --- Introducing the Small Gain Stage --- p.3-4 / Chapter 3.4 --- Concept of the Proposed Virtual Two-Stage Miller Compensated Amplifier --- p.3-7 / Chapter 3.5 --- Comparisons with Bandwidth Enhanced Miller Compensated Two-Stage Amplifier --- p.3-9 / Chapter 3.6 --- Proposed Virtual Two-Stage Amplifier with Simple Miller Compensation --- p.3-13 / Chapter 3.7 --- Design Considerations and Expected Performance --- p.3-15 / Chapter 3.8 --- Experimental Result --- p.3-18 / Chapter 3.9 --- Conclusions of Chapter --- p.3-31 / References --- p.3-32 / Chapter Chapter 4 --- Implementation of the Low-Pass Filter / Chapter 4.1 --- Implementation of the Low-Pass Filter --- p.4-1 / Chapter 4.2 --- Experimental Result --- p.4-4 / Chapter 4.3 --- Conclusion of Chapter --- p.4-7 / Reference --- p.4-8 / Chapter Chapter 5 --- Conclusion and Future Work / Chapter 5.1 --- Conclusion of Thesis --- p.5-1 / Chapter 5.2 --- Suggestion for Future Work --- p.5-2
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_328544 |
| Date | January 2012 |
| Contributors | Poon, Hiu Ching., Chinese University of Hong Kong Graduate School. Division of Electronic Engineering. |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, bibliography |
| Format | electronic resource, electronic resource, remote, 1 online resource (1 v. (various pagings)) : ill. (some col.) |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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