Variable gain amplifier having linear-in-decibel...

Details Variable gain amplifier having linear-in-decibel... Variable gain amplifier having linear-in-decibel...

2007-08-28

2007-08-28

Pascal, Robert (Department: 2817)

Amplifiers

With semiconductor amplifying device

Including differential amplifier

Reexamination Certificate

active

11654818

ABSTRACT:
A variable gain amplifier includes a variable resistor, a first MOS transistor and a second MOS transistor. The variable resistor has one end coupled to a ground. The first MOS transistor with transconductance 2gm amplifies a first differential input signal to provide a first current between an output node and other end of the variable resistor. The second MOS transistor with transconductance gm amplifies a second differential input signal to provide a second current between the output node and the ground. The variable resistor can be implemented using a MOS transistor operating in a linear region. The variable gain amplifier has an exponentially varying output current responsive to adjusting a gate voltage of the MOS transistor. Therefore, the transconductance of the variable gain amplifier has a linear-in-decibel characteristic.

REFERENCES:
patent: 4859961 (1989-08-01), Davenport
patent: 5006816 (1991-04-01), Koide
patent: 5999053 (1999-12-01), Eschauzier
patent: 6366168 (2002-04-01), Zheng et al.
patent: 6788144 (2004-09-01), Honda
patent: 6933783 (2005-08-01), Banba
patent: 7081785 (2006-07-01), Mori et al.
patent: 7151409 (2006-12-01), Koen et al.
patent: 2003/0132803 (2003-07-01), Matsumoto et al.
patent: 3-38919 (1991-02-01), None
patent: 5-29856 (1993-02-01), None
patent: 2001-196880 (2001-07-01), None

Affiliated with

Also associated with

Rating

Variable gain amplifier having linear-in-decibel... 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 amplifier having linear-in-decibel..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Variable gain amplifier having linear-in-decibel... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3879131