D類功率放大器一般應用在高效率的電路當中，應用在助聽器的系統當中，除了需較高的效率之外，我們也求較低的工作電壓以及較低的功率，而操作頻率是屬於低頻的訊號。
我們的電路設計是基於TSMC 035 製程技術，電路的工作電壓是1.5V和允許的輸入信號頻率是4KHz，經模擬之後，更進一步的證明出D類放大器是一種高效率的放大器。當我們使用2KHz的操作頻率和振幅是0.3V的輸入訊號時，我們可以得到最大的總諧波失真是0.63%和靜態電流是4uA以及83.6%的效率。

Class D power amplifier applies in high efficiency circuit. In hearing aid system, we require high power efficiency, low-voltage and low-power. The operation of frequency is low frequency.

All the circuits are designed based on the TSMC 035 CMOS process technology. The supply voltage is 1.5V and the input signal is 4KHz. Simulation results show that the Class D power efficiency is high efficiency amplifier. When 0.3V of 2KHz input signal is applied, The maximum THD is 0.63% and static current is 4uA and the efficiency is 83.6%.

Abstract

Chapter 1　Introduction 1
1.1 Basic Concept 1
1.2 Principles of Class D Power Amplifier 2
1.3 A Structure of Pulse Width Modulation 4

Chapter 2 Previous Class D Circuits 7
2.1 Mead’s Circuit 7
2.1.1 Basic Theorem and Circuit 7
2.1.2 Problems of this Circuit 9
2.2 Previous Improvement Circuit 13

Chapter 3　The Proposed Circuit 15
3.1 Basic Concept and Idea 15
3.2 Improvement Circuit 17
3.2.1 Triangular Wave Generation 19
3.2.2 Output Stage 21
3.2.3 Effect of Output Stage on Resistance 22
3.2.4 Effect of Harmonic Distortion 24
3.2.5 The Power Efficiency 26

Chapter 4　 Simulation Results and Discussions 27
Chapter 5　Conclusion 34
Reference

Reference


[1] Meng-Tong Tan, Joseph S. Chang, Hock-Chuan Chua, and Bah-Hwee Gwee, “An investigation into the parameters affecting total harmonic distortion in low-voltage low-power class-d amplifiers,” IEEE Transactions on Circuits and Systems Vol. 50, No, 10, OCTOBER 2003.

[2] Bah-Hwee Gwee, Joseph S. Chang, Victor Adrian and Haryanto Amir, “A novel sampling process and pulse generator for a low distortion digital pulse-width modulator for digital class D amplifiers,” Circuits and Systems, 2003. ISCAS ’03. Proceedings of the 2003 International Symposium on, Volume : 4, 25-28 May.

[3] Joseph S. Chang, Meng-Tong Tan, Zhihong Cheng, and Yit-Chow Tong, “Analysis and design of power efficient class D amplifier output stages,” IEEE Transactions on Circuits and Systems, Vol. 47, No.6, JUNE 2000.

[4] M.C. Killion and G. Village, “Class D hearing aid amp,” US Patent No. 4,689,819, 1987.

[5] M.T. Tan, J.S. Chang and Y.C. Tong, “A novel self-tuning pulse width modulator based on master-slave architecture for a class D amplifier,” Circuits and Systems, 1999. ISCAS ’99. Proceedings of the 1999 IEEE International Symposium on, Volume: 2, 30 May-2 June 1999.

[6] M.T. Tan, J.S. Chang, Z.H. Chang Y.C. Tong, “A novel self-error correction pulse width modulator for a class D amplifier for hearing instruments,” Circuits and Systems, 1998. ISCAS ’98. Proceeding of the 1998 IEEE International Symposium on, Volume : 1, 31 May-3 June 1998.

[7] R. Jacob Baker, Harry W. Li and David E. Boyce, “CMOS Circuit Design, Layout, and Simulation,” The Institute of Electrical and Electronics Engineers, Inc., New York, pp.463-503

[8] Dallas Maxim, “Class D audio amplifier output filter optimization,” www.maxim-ic.com/an624, Apr 01, 2002.

[9] Norbert R. Malik, “Electronic circuits analysis, simulation, and design,” Prentice Hall International Editions, Vol. 10, pp. 751-798, 1995.