臺灣博碩士論文加值系統

　D類放大器由於有較高的效率，因此逐漸的備受重視，然而由於切換式的操作，所以D類放大器比起傳統的線性放大器而言，線性度是較需要加強的地方，因此本論文中利用負回授的機制來降低諧波失真，並提高其整體的線性度。此外亦利用非同步的控制訊號去驅動功率電晶體，避免因為功率電晶體同時導通而產生貫通電流，造成功率消耗及電路損毀。再者也加入了短路電流機制，避免電路因為接線問題，造成短路而導致短路電流的發生並進而損毀整個系統。
　本篇論文實現出一個利用脈衝寬度調變的單端輸入，雙端輸出的D類音頻放大器。這個脈衝寬度調變的D類音頻放大器是採用台灣積體電路製造股份有限公司所提供的0.35um 2P4M 3.3V/5V 混合訊號互補式金氧半製程來製造。晶片的工作面積大約 ，總面積則為 。經由模擬結果可知訊號雜訊比在音頻範圍內可達到90dB，總諧波失真大約0.045%，整體的效率則為82%。詳細的介紹及電路設計將在後面的章節中陸續介紹。

　The Class-D amplifier, for its high efficiency, has drawn much attentions recently. However, due to its switching operation, the linearity is needed to be improved by comparing with conventional linear amplifiers. Therefore, the negative feedback is applied in this thesis to reduce the harmonic distortion for better linearity. In addition, to avoid the shoot through current due to both power transistors are switched on at the same time, the dead time control is adopted. The over-current protection circuit is also added to prevent the short circuit by poor wire connection. The large current induced by the short circuit would destroy the overall system potentially.
　A single-ended input, differential output Class-D audio amplifier with pulse-width modulation (PWM) is implemented with TSMC 0.35um 2P4M 3.3V/5V Mixed Signal CMOS process. The active area of the amplifier is around 0.99 x 0.93 mm2, and the total area is 1.3 x 1.3 mm2. The simulation results show 90dB of SNR and 82% of efficiency can be achieved. THD is around 0.045% while Class-D amplifier deliver 240mW.

Chapter 1 Introduction(1)
　1.1 Background(1)
　1.2 Motivation(2)
　1.3 Organization(2)

Chapter 2 Fundamentals of Class-D Audio Amplifier(3)
　2.1 Linear Audio Amplifier(3)
　　2.1.1 Class-A Amplifier(4)
　　2.1.2 Class-B Amplifier(5)
　　2.1.3 Class-AB Amplifier(6)
　　2.1.4 Summary(7)
　2.2 Classifications of Class-D Audio Amplifiers(7)
　　2.2.1 Pulse-Width Modulation (PWM)(7)
　　2.2.2 Sigma-Delta Modulation (SDM)(8)
　　2.2.3 One-Cycle Control(9)
　　2.2.4 Rectangular Wave Delta Modulation (RWDM)(10)
　2.3 Operating Principle of PWM Class-D Audio Amplifier(11)
　2.4 Classifications of Output Stage(12)
　2.5 Design Issues(14)
　　2.5.1 Efficiency(15)
　　2.5.2 SNR(16)
　　2.5.3 THD(16)
　　2.5.4 Noise Source(17)

Chapter 3 System Design of Class-D Audio Amplifier(18)
　3.1 Open-loop Class-D Audio Amplifier(18)
　　3.1.1 Amplification(18)
　　3.1.2 Dead-Time Control(20)
　3.2 Feedback(22)
　　3.2.1 Feedback Topology(22)
　　3.2.2 Analysis of Feedack Influence on THD(25)
　3.3 Output Filter(27)
　3.4 Over-current Protection(30)

Chapter 4 Circuits Design of Class-D Amplifier(32)
　4.1 Architecture of Class-D Amplifier(32)
　4.2 Power Transistor(34)
　4.3 Triangular Wave Generator(36)
　4.4 PWM Generator(39)
　4.5 Non-Overlapping Gate-Driver(42)
　4.6 Current Sensor(47)
　4.7 Current Limit Circuit(50)
　4.8 Operational Amplifier(51)
　4.9 Comparator(55)
　4.10 Feedback(58)
　　4.10.1 Summing Circuit(58)
　　4.10.2 Feedback Circuit(60)
　4.11 System Pre-Layout Simulation(62)
　4.12 System Post-Layout Simulation(69)

Chapter 5 Layout and Measurement(73)
　5.1 Layout and Floor-plan(73)
　5.2 Measurement Setup(75)

Chapter 6 Conclusions and Future Work(76)

References(77)

Reference

[1]Jorge Varona Salazar, “A Low-Voltage Fully-Monolithic Delta-Sigma Based Class-D Audio Amplifier in 0.18um CMOS”, Ph.D Dissertation, UMI
[2]Alejandro Raul Oliva, “Topics on Switching Audio Amplifiers”, Ph.D Dissertation, UMI
[3]Chen Hai; Wu Xiaobo, “A Class D Audio Power Amplifier with High-Efficiency and Low-Distortion”, Design Automation Conference, 2005. Proceedings of the ASP-DAC 2005. Asia and South Pacific, Vol. 2, 18-21 Jan. 2005
[4]Brett Forejt, senior Member, IEEE, Vijay Rentala, Jose Duilio Arteaga, and Gangadhar Burra, “A 700+-mW Class D Design With Direct Battery Hookup in a 90-nm Process”, Solid-State Circuits, IEEE, Vol. 40, No. 9 September 2005
[5]Marco Berkhout, “Integrated Class D Amplifier”, Ph. D Dissertation, AES
[6]Mark Bloechl, Mohannad Bataineh, and Dale Harrell, “Class D Switching Power Amplifiers: Theory, Design, and Performance”, Department of Electrical and Computer Engineering University of West Florida
[7]Lai, Z.; Smedley, K.M, “A New Extension of One-Cycle Control and Its Application to Switching Power Amplifiers”, IEEE Transactions on Power Electronics, Vol 11, No1, Jan. 1996
[8]Antonio Ginart, “Single Ended Switching Analog Audio Amplifier with Dead Zone”, Ph.D Dissertation, UMI
[9]Simon Cimin Li, Vincent Chia-Chang Lin, Krissanapong Nandhasri, and Jitkasame Ngarmnil, “New High-Efficiency 2.5V/0.45W RWDM Class-D Audio Amplifier for Portable Consumer Electronics”, IEEE Transactions on CAS I Vol. 52, No. 9, Sep. 2005.
[10]Nandhasri, K.; Ngarmnil, J.; Moolpho, K., “A 2.8V RWDM BTL Class-D Power Amplifier Using an FGMOS Comparator”, Circuits and Systems, 2002. ISCAS 2002. IEEE International Symposium on Vol. 5, May 2002
[11]Patrick Muggler, Wayne Chen, Clif Jones, Paras Dagli, Navid Yazdi, “A Filter Free Class D Audio Amplifier with 86% Power Efficiency”, Circuits and Systems, 2004. ISCAS ’04. Proceedings of the 2004 International Symposium on, Volume 1, 23-26 May 2004
[12]“International IOR Rectifier Application Note: Class D Audio Amplifier Basics”, http://www.irf.com
[13]Cary Delano, “Designing with Switching Amplifier for Performance And Reliability”, Tripath Technology Application Note
[14]Meng Tong Tan; Chang, J.S.; Hock Chuan Chua; Bah Hwee Gwee, “An Investigation Into the Parameters Affecting Total Harmonic Distortion in Low-Voltage Low-Power Class-D Amplifiers”, Circuits and Systems I: Fundamental Theory and Applications, IEEE Transactions on, Volume 50, Issue 10, Oct. 2003
[15]Karsten Nielsen, “Linearity and Efficiency Performance of Switching Audio Power Amplifier Output Stages – A Fundamental Analysis”, Ph. D Dissertation, AES
[16]“Mono Class_D Amplifiers”,AN1013 Application Note, http://www.st.com/stonline/products/literature/an/5694.pdf#search='Mono%20Class_D%20Amplifiers’
[17]“Power Electronics: converters, applications and design”, Second Edition, Mohan, Undeland, Robbins
[18]I.D. Mosely, P.H. Mellor and C.M. Bingham, “Effect of dead time on harmonic distortion in Class-D power amplifiers”, Electronics Letters, Volume 35, No. 12, pp950-952, June 1999
[19]Karsten Nielsen, “High-Fidelity PWM-Based Amplifier Concept for Active Loudspeaker Systems with Very Low Energy Consumption”, AES, Vol. 45, No. 7/8 1997 July/August
[20]Joseph S. Chang, Bah Hwee Gwee, Yong Seng Lon and Meng Tong Tan, “A Novel Low-Power Low-Voltage Class D Amplifier with Feedback for Improving THD, Power Efficiency and Gain Linearity”, Circuits and Systems, 2001. ISCAS 2001. The 2001 IEEE International Symposium on, Volume 1, 6-9 May 2001
[21]Marco Berkhout, “Integrated Overcurrent Protection System for Class-D Audio Power Amplifiers”, Solid-State Circuits, IEEE, Vol. 40, No. 11, November 2005
[22]Darwish, M.; Huang, J.; Liu, M.; Shekar, M.S.; Williams, R.; Cornell, M., “Scaling issues in lateral power MOSFETs” Power Semiconductor Devices and ICs, 1998. ISPSD 98, Proceedings of the 10th International Symposium on 3-6 June 1998
[23]“Introduction to Electroacousitcs and Audio Amplifier Design”, Second Edition – Revised Printing, by W. Marshall Leach , Jr., Publicated by Kendall/Hunt
[24]Wei-Shang Chu, K. Wayne Current, “A Rail-to-Rail Input-Range CMOS Voltage Comparator”, Circuits and Systems, 1997 Proceedings of the 40th Midwest Symposium on, Volume 1, 3-6 Aug. 1997
[25]Cheung Fai Lee, Mok, P.K.T, “A monolithic current-mode CMOS DC-DC converter with on-chip current sensing technique”, Solid-State Circuits, IEEE, Vol. 39, No. 1, Jan, 2004
[26]C.Y. Wang, “A Current-Mode Buck Regulator with an Adjusted-Slope Compensation Ramp”, graduate thesis, MSIC Lab. Department of Electrical Engineering, National Cheng-Kung University, Tainan City, Taiwan, Republic of China”
[27]Marco Berkhout, “An Integrated 200-W Class-D Audio Amplifier”, Solid-State Circuits, IEEE, Volume 38, Issue 7, July 2003
[28]Paul Morrow, Eric Gaalaas, Oliver McCarthy, “A 20-W stereo class-D audio output power stage in 0.6-/spl mu/m BCDMOS technology”, Solid-State Circuits, IEEE, Volume 39, Issue 11, Nov. 2004