Amplifiers – With semiconductor amplifying device – Including differential amplifier
Patent
1996-06-12
1999-03-09
Mottola, Steven
Amplifiers
With semiconductor amplifying device
Including differential amplifier
330257, H03F 345
Patent
active
058806369
ABSTRACT:
In a technique for reducing the transconductance of an input stage of an operational amplifier, the phase delay which the active load current mirror introduces into the single path is utilized in a way such that the phase delay of the overall stage is less than the delay of the primary differential pair. It is a mathematical fact that when two sinusoidal signals of the same frequency are added together, the result is also sinusoidal. Considering two such signals, the second of which has a phase lag with respect to the first, if the two signals are combined by the addition of ordinates, the resulting sinusoid also has a phase lag. However, if the second signal is instead subtracted from the first, then the resulting sinusoid has a phase lead with resect to the first signal. The present invention makes use of this phenomenon by causing the delayed mirror signal to be subtracted from, rather than added to, the primary signal. This produces a differential transconductance stage with less negative phase shift than that of the prior art, in fact less than that of the primary differential pair alone.
REFERENCES:
patent: 5182526 (1993-01-01), Nelson
Mottola Steven
National Semiconductor Corporation
LandOfFree
Input stage for operational amplifier utilizing phase delay of a does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Input stage for operational amplifier utilizing phase delay of a, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Input stage for operational amplifier utilizing phase delay of a will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1325284