Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 31819
A Novel Logarithmic Current-Controlled Current Amplifier (LCCA)

Authors: Karama M. AL-Tamimi, Munir A. Al-Absi


A new OTA-based logarithmic-control variable gain current amplifier (LCCA) is presented. It consists of two Operational Transconductance Amplifier (OTA) and two PMOS transistors biased in weak inversion region. The circuit operates from 0.6V DC power supply and consumes 0.6 μW. The linear-dB controllable output range is 43 dB with maximum error less than 0.5dB. The functionality of the proposed design was confirmed using HSPICE in 0.35μm CMOS process technology.

Keywords: LCCA, OTA, Logarithmic, VGA, Weak inversion, Current-mode

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1868


[1] Thomas L. Floyd, Electronic Devices (Conventional Flow Version), 6th ed. (Prentice Hall, 2001).
[2] V.T.S. Vintola et al., "Variable-gain power amplifier for mobile WCDMA applications," IEEE Transactions on Microwave Theory and Techniques 49 (December 2001): 2464-2471.
[3] D. Coffing et al., "A variable gain amplifier with 50-dB control range for 900-MHz applications," IEEE Journal of Solid-State Circuits 2 (September 2002): 1169-1175.
[4] B. Sewiolo, G. Fischer, and R. Weigel, "A 30 GHz Variable Gain Amplifier With High Output Voltage Swing for Ultra-Wideband Radar," IEEE Microwave and Wireless Components Letters 19 (September 2009): 590-592.
[5] K. Hadidi and H. Kobayashi, "A 25 MHz 20 dB variable gain amplifier" (Instrumentation and Measurement Technology Conference, 1994. IMTC/94. Conference Proceedings. 10th Anniversary. Advanced Technologies in I & M., 1994 IEEE), vol.2, pp. 780-783, May 1994
[6] Liu W and Liu S-I, "Low Voltage and Low Power CMOS Exponential- Control Variable-Gain Amplifier," IEICE Trans Fundam Electron Commun Comput Sci (Inst Electron Inf Commun Eng) E87-A, no. 4 (2004): 952-954.
[7] C. -C Chang, M. -L Lin, and S. -I Liu, "CMOS current-mode exponential-control variable-gain amplifier," Electronics Letters 37, no. 14 (July 5, 2001): 868-869.
[8] W. Liu, S. -I Liu, and S. -K Wei, "CMOS exponential-control variable gain amplifiers," Circuits, Devices and Systems, IEE Proceedings - 151, no. 2 (April 12, 2004): 83- 86.
[9] Po-Chiun Huang, Li-Yu Chiou, and Chorng-Kuang Wang, "A 3.3-V CMOS wideband exponential control variable-gain-amplifier," in Proceedings of the 1998 IEEE International Symposium on Circuits and Systems, 1998. ISCAS -98, vol. 1 (presented at the Proceedings of the 1998 IEEE International Symposium on Circuits and Systems, 1998. ISCAS -98, IEEE, 1998), 285-288 vol.1.
[10] John M. Tammone, Jr., "United States Patent: 6229374 - Variable gain amplifiers and methods having a logarithmic gain control function", May 8, 2001.
[11] M. Mizutani, "Patent 4628276" - Logarithmically linearly controlled variable gain amplifier (Google Patents, December 14, 1984).
[12] W. Liu and S. I Liu, "Low-voltage and low-power CMOS voltage-tocurrent converter," IEICE transactions on electronics 87, no. 6 (2004): 1029-1032.
[13] Weihsing Liu, Wei-Lung Mao, and Jyh Sheen, "A Low-power and Lowvoltage Cube-law Circuit Design using MOSFETs," in Electron Devices and Solid-State Circuits, 2007. EDSSC 2007. IEEE Conference on, 2007, 829-832.
[14] A. Nag and R.P. Paily, "Low power squaring and square root circuits using subthreshold MOS transistors," in Emerging Trends in Electronic and Photonic Devices & Systems, 2009. ELECTRO -09. International Conference on, 2009, 96-99.
[15] M.A. Al-Absi, "Low-voltage and low-power CMOS current-mode divider and 1/x circuit," in Electronic Devices, Systems and Applications (ICEDSA), 2010 Intl Conf on, 2010, 245-247.
[16] F. Serra-Graells and J.L. Huertas, "Low-voltage CMOS subthreshold log amplification and AGC," Circuits, Devices and Systems, IEE Proceedings - 152, no. 1 (2005): 61-70.
[17] C.-H. Kao, W.-P. Lin, and C.-S. Hsieh, "Low-voltage low-power current mode exponential circuit," Circuits, Devices and Systems, IEE Proceedings - (2005): 633-635.
[18] J. Pimentel, F. Salazar, M. Pacheco, and Y. Gavriel, "Very-low-power analog cells in CMOS," 2000 Proc. 43rd IEEE Midwest Symposium on Circuits and Systems, vol.1, pp.328 -331, 2000.