5-1.3 虛擬指數函數電路
圖 5.3 虛擬指數函數電路佈局圖
5-1.4 柴比雪夫有理數電路
圖 5.4 柴比雪夫有理數電路佈局圖
5-2 pre-simulation 5-2.1 最佳近似法電路
TT
SS
SF
FS
FF
圖 5.5 最佳近似法電路(
I
n/I
d)dB 5 種 corner 比較圖5-2.2 柴比雪夫多項式之經濟化電路
圖 5.6 柴比雪夫多項式之經濟化電路(
I
out)dB 5 種 corner 比較圖5-2.3 虛擬指數函數電路
圖 5.7 虛擬指數函數電路(
I
n/I
d)dB 5 種 corner 比較圖5-2.4 柴比雪夫有理數電路
圖 5.8 柴比雪夫有理數電路(
I
n/I
d)dB 5 種 corner 比較圖5-3 post-simulation 5-3.1 最佳近似法電路
圖 5.9 最佳近似法電路(
I
n/I
d)dB post simulation 圖5-3.2 柴比雪夫多項式之經濟化電路
圖 5.10 柴比雪夫多項式之經濟化電路(
I
out)dB post simulation 圖5-3.3 虛擬指數函數電路
5-3.4 柴比雪夫有理數電路
圖 5.12 柴比雪夫有理數電路(
I
n/I
d)dB post simulation 圖
第六章 結論與未來研究
本篇論文使用柴比雪夫多項式近似法及最佳近似法實現之電流模式的指數函 數產生器，具有較高的輸入範圍和較高的dB輸出範圍，可以應用在不同需要的可 變增益放大器或自動增益控制迴路中。例如通訊系統中的中頻放大器，隨著距離 的遠近，中頻放大器就需要有不同的增益，因此我們可以在不增加太多電路的條 件下擴大增益的範圍，所以本篇論文的指數函數產生器就有此好處。
在未來的研究方面，隨著半導體製程技術的發展，及微米CMOS 的技術出現，
未來電路的趨勢就是朝低操作電壓、低功率消耗發展。如何讓現有發展的電路適 用在低操作電壓，又不能改變其原有特性，或是研發出ㄧ新的電路適用在低操作 電壓又有其原有電路的特性，將會是一項充滿挑戰的課題。
參考文獻
[1] Sahota, G.S., and Persico, C.J. , “High dynamic range variable-gain amplifier for CDMA wireless applications,” Solid-State Circuits Conference, 1997. Digest of Technical Papers. 44th ISSCC. ,1997 IEEE International 6-8 Feb. 1997 Page(s):374 - 375, 488
[2] Quoc-Hoang Duong, Hoang-Nam Duong, Trung-Kien Nguyen, and Sang-Gug Lee,
“A 95-dB Linear Low-Power Variable Gain Amplifier,” IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS—I: REGULAR PAPERS, VOL. 53, NO. 8, AUGUST 2006.
[3] W. Liu, S.-I. Liu and S.-K. Wei, “CMOS exponential-control variable gain amplifiers,” IEE Proc.-Circuits Devices Syst., Vol. 151, No. 2, April 2004.
[4] T. Arthansiri and V. Kasemsuwan, “Current-mode pseudo-exponential-control variable-gain amplifier using fourth-order Taylor’s series approximation,”
ELECTRONICS LETTERS ,Vol. 42 ,No. 7 , 30th , March 2006.
[5] R. Harijani, “A Low-power CMOS VGA for 50 Mb/k Disk Drive Read Channels ,”IEEE Trans. Circuits and Syst vol. 42, no. 6, pp. 370-376, June, 1995.
[6] Okjune Jeon, Robert M. Fox, and Brent A. Myers, “Analog AGC Circuitry for a CMOS WLAN Receiver,” IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL.
41, NO. 10, OCTOBER 2006.
[7] Chang, C.C., and Liu, S.I. , “Current-mode pseudo-exponential circuit with tunable input range,” Electron. Lett., (16) , pp. 1335–1336, 2000, 36.
[8] Quoc-Hoang Duong. Hoang-Nam Duong, Trung-Kien Nguyen and Sang-Gug Lee,
“All CMOS current-mode exponential function generator,” Advanced Communication Technology, 2004. The 6th International Conference on Volume 1, 2004 Page(s):528 – 531.
[9] Burden, R.L., and Faires, J.D. , “Numerical analysis”(Brooks/Cole Publishing Company, Belmont, CA, 8th edn., 2004).
[10] H. Wasaki, Y. Horio and S. Nakamura, “Current multiplier/divider circuit,”
Electronics Letters ,Vol 27, Issue 6, Page(s):504 – 506, March 1991 .
[11] A. Motanemd, C. Hwang and M. Ismail, “CMOS exponential current-to-voltage converter,” Elect. Let., vol. 33, no. 12, pp, 998-1000, June 1997.
[12] K. Bult and H. W, “A Class of Analog CMOS Circuits Based on the Square-Law Characteristic of an MOS Transistor in Saturation,” IEEE JOURNAL OF
SOLID-STATE CIRCUITS, VOL. SC-22, NO. 3, JUNE 1987.
[13] Weihsing Liu, Shen-Iuan Liu, Senior Member, IEEE, and Shui-Ken Wei,
“CMOS Current-Mode Divider and Its Applications,” IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS—II: EXPRESS BRIEFS, VOL. 52, NO. 3, MARCH 2005.
[14] Chang, C.C., and Liu, S.I., “Pseudo-exponential function for MOSFETs in saturation,” IEEE Trans. Circuits Syst. II, 2000, 47, (11), pp. 1318–1321.
[15] Chang, C.C., Lin, M.L., and Liu, S.I , “CMOS current-mode exponential control variable-gain amplifier,” Electron Lett., 2001, 37, (14), pp. 868–869.
[16] Weihsing Liu and Shen-Iuan Liu, “CMOS exponential function generator,”
ELECTRONICS LETERS 9th January 2003 Vol. 39 No. 1.
[17] Carlos A. De La Cruz Blas and Antonio López-Martín, “Novel Low-Power High-dB Range CMOS Pseudo-Exponential Cells,” ETRI Journal, Volume 28, Number 6, December 2006.
[18] Quoc-Hoang Duong, Hoang-Nam Duong, Trung-Kien Nguyen, and Sang-Gug Lee, “Pseudo-exponential current-to-voltage converter,” Advanced Communication Technology, 2004. The 6th International Conference on Volume 1, 2004