Amplifiers – With semiconductor amplifying device – Including gain control means
Reexamination Certificate
2006-03-31
2008-03-04
Choe, Henry (Department: 2817)
Amplifiers
With semiconductor amplifying device
Including gain control means
C330S278000
Reexamination Certificate
active
07339434
ABSTRACT:
A variable gain amplifier uses a geometric ladder circuit that produces a transfer function having substantially uniform steps measured in dB. Where the ladder has a plurality of substantially identical resistor rungs of a first resistance, one stile that is a conductor connecting the rungs, and another having a series of substantially identical resistors of a second resistance, then for identical inputs at different rungs, the output signal at an end of the ladder is attenuated by a number of substantially equal steps, one for each rung between input and output. For a ladder with a base rung R, an output at an end opposite the base rung, stile resistors of resistance αR, and other rungs all of resistance (1+(1/α))R, the step size is 20 log10(1+α). By using such ladders in op-amp feedback loops, chaining different stages with different values of α, coarse and fine gain adjustment can be provided.
REFERENCES:
patent: 4467286 (1984-08-01), Stitt
patent: 5128675 (1992-07-01), Harada
patent: 5394019 (1995-02-01), Audy
patent: 5781140 (1998-07-01), Kao
patent: 5973566 (1999-10-01), Leiby
patent: 6445248 (2002-09-01), Gilbert
patent: 6882294 (2005-04-01), Linder et al.
patent: 6975261 (2005-12-01), Isham
patent: 7102441 (2006-09-01), Lee et al.
patent: 7154421 (2006-12-01), Devendorf et al.
Fattaruso, J.W., “Nonlinear analog function synthesis with MOS technology,” Dissertation thesis submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Engineering in the Graduate Division of the University of California, Berkeley.
Chien George
Shirvani-Mahdavi Alireza
Choe Henry
Marvell International Ltd.
LandOfFree
Linear-in-dB variable gain amplifier using geometric ladder... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Linear-in-dB variable gain amplifier using geometric ladder..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Linear-in-dB variable gain amplifier using geometric ladder... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3961877