Amplifiers – With semiconductor amplifying device – Including differential amplifier
Patent
1998-05-26
1999-03-23
Mottola, Steven J.
Amplifiers
With semiconductor amplifying device
Including differential amplifier
330254, H03F 345
Patent
active
058865799
ABSTRACT:
A variable gain amplifier includes an input transconductor having a transconductance that is variable in response to a first control signal, an output circuit having a transresistance that is variable in response to a second control signal and a gain controller responsive to a gain control signal x for providing the first and second control signals to the input transconductor and the output circuit. The amplifier has a voltage gain equal to the product of the transconductance and the transresistance. When the first control signal is a function (1+x) of the gain control signal and the second control signal is a function (1-x) of the gain control signal, the voltage gain of the amplifier is approximately an exponential function of the gain control signal.
REFERENCES:
patent: 3919654 (1975-11-01), Toumani
patent: 4520324 (1985-05-01), Jett et al.
patent: 4934770 (1990-06-01), Anderson et al.
patent: 5668502 (1997-09-01), Rijns
patent: 5757230 (1998-05-01), Mangelsdorf
Ono, K., etl., "Design of Low-Distortion MOS OTA Based on Cross-Coupled Differential Amplifier and its Application for Active Filters", IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, vol. E77-A, No. 2, 1 Feb. 1994, pp. 363-370.
Patent Abstracts of Japan, vol. 017, No. 476 (E-1424), 30 Aug. 1993 and JP 05 114836 A (Toshiba Corp.), 7 May 1993.
Ramesh Harjani, A Low Power CMOS VGA for 50 Mb/s Disk Drive Read Channels Jun. 1995, pp. 370-376, IEEE Transactions on Circuits and Systems, Analog and Digital Signal Processing, vol. 42, No. 6.
Zhenhua Wang, A CMOS Four-Quadrant Analog Multiplier With Single-Ended Voltage Output And Improved Temperature Performance, Sep. 1991, pp. 1293-1301, IEEE Journal Of Solid-State Circuits, vol. 26, No. 9.
Zhenhua Wang & Walter Guggenbuhl. A Voltage-Controllable Linear MOS Transconductor Using Bias Offset Technique, Feb. 1990, pp. 315-317, IEEE Journal of Solid-State Circuits, No.1.
Analog Devices Inc.
Mottola Steven J.
LandOfFree
Variable gain CMOS amplifier does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Variable gain CMOS amplifier, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Variable gain CMOS amplifier will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2130280