Miscellaneous active electrical nonlinear devices – circuits – and – Specific input to output function – By integrating
Reexamination Certificate
1998-04-03
2003-09-02
Callahan, Timothy P. (Department: 2816)
Miscellaneous active electrical nonlinear devices, circuits, and
Specific input to output function
By integrating
C327S374000, C330S009000, C341S172000
Reexamination Certificate
active
06614285
ABSTRACT:
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
1. Technical Field
The invention relates to integration and particularly to switched capacitor active integration having very low distortion and noise where power dissipation is a concern.
2. Description of Related Art
Amplifiers are well known in the art. For high precision switched capacitor circuits and ADC's the class A operational amplifier is well suited. A class A amplifier dissipates a constant amount of power independent on the input or output conditions. This is well suited for low-distortion systems, but poor from a power dissipation point-of-view.
Integrators are also known in the art. Some integrators are passive, in that they are made up of only components such as resistors or capacitors. Other integrators are active, using an amplifier to transfer the signal to an integration element, usually a capacitor. For low distortion, low noise applications, the active integrator is best suited. With CMOS integrated circuits, the switched capacitor integrator, and more generally, the switched capacitor filter is a commonly used circuit. In a switched capacitor circuit, a voltage is sampled on a capacitor in one phase, and the resulting charge is transferred in a second phase. This repeated moving of charge packets results in a current flow. This switched capacitor “branch” behaves much like a resistor when viewed at a low frequency. Its advantage in CMOS integrated circuits include manufacturability and matching to other elements. Delta-sigma modulators are also known which provide a series of binary signals at an output which in a certain frequency range is a digital representation of an input signal.
Systems for conducting seismic exploration are well known in the art. On land, a plurality of transducers are deployed over a region and configured to receive reflections of acoustic signals from different geophysical layers beneath the surface of the earth. Seismic sensors are connected over cables to signal conditioning, digitization and digital recording equipment. When utilizing a seismic system, a strong acoustic signal is generated by, for example, setting off an explosion or by utilizing an acoustic signal generator having a relatively high power output. Reflections of the acoustic signals from the geographical layers are then received at the seismic sensors deployed over a given area and the signals recorded, typically, for later analysis.
One problem with seismic exploration is that it frequently occurs in remote areas. As a result, transportation becomes a problem. Such remote areas typically do not have sources of electrical power. Accordingly, when undertaking seismic exploration in a remote area, electric power must be transported in. Whether the transportation occurs by air or by people physically hiking into a rugged area, weight is a significant factor. A common form of power source utilized in seismic exploration makes use of batteries. Batteries are generally heavy. As a result, any power saving that can be achieved results in significantly reduced costs for a particular exploration.
When seismic exploration is undertaken over water, commonly an array of seismic sensors is towed behind a boat using cables which can extend over a mile in length. Like on land, an acoustic generator is utilized to generate an acoustic impulse, reflections of which occur at geophysical boundaries. Those reflections are detected by the seismic sensors towed behind the boat and recorded, typically, for later analysis. In any seismic environment, it is important to reproduce the captured signals with great precision to insure that the information of interest can be reliably obtained. Like on land, power dissipation is a concern in the marine application. This is because of the problem distributing power over the length of the towed cable.
SUMMARY OF THE INVENTION
An integrator circuit, and particularly one using an amplifier with a switched capacitor input circuit, is shown which achieves very low distortion and noise with minimum power consumption utilizing an amplifier design and step size set to reduce load capacitance. The amplifier is supplied with different levels of power during different operational phases.
REFERENCES:
patent: 3801923 (1974-04-01), Russell et al.
patent: 4066992 (1978-01-01), Buller et al.
patent: 4138614 (1979-02-01), Ochi
patent: 4502019 (1985-02-01), Van Roermund
patent: 4521743 (1985-06-01), Heimer
patent: 4712021 (1987-12-01), Gollinger
patent: 4806791 (1989-02-01), Mizuide
patent: 4862016 (1989-08-01), Genrich
patent: 4934770 (1990-06-01), Anderson et al.
patent: 4935703 (1990-06-01), Poletto
patent: 5055846 (1991-10-01), Welland
patent: 5091662 (1992-02-01), Yung et al.
patent: 5111205 (1992-05-01), Morlon
patent: 5124576 (1992-06-01), Jensen
patent: 5180932 (1993-01-01), Bengel
patent: 5311181 (1994-05-01), Ferguson, Jr. et al.
patent: 5343164 (1994-08-01), Holmdahl
patent: 5351050 (1994-09-01), Thompson et al.
patent: 5465270 (1995-11-01), Beauducel et al.
patent: 5471171 (1995-11-01), Itakura et al.
patent: 5510754 (1996-04-01), Moraveji et al.
patent: 5530384 (1996-06-01), Lee et al.
patent: 5600318 (1997-02-01), Li
patent: 5606320 (1997-02-01), Kleks
patent: 5644257 (1997-07-01), Kerth et al.
patent: 5661434 (1997-08-01), Brozovich et al.
patent: 5691720 (1997-11-01), Wang et al.
patent: 5719573 (1998-02-01), Leung et al.
patent: 5724037 (1998-03-01), Lee
patent: 5734272 (1998-03-01), Belot et al.
patent: 5736950 (1998-04-01), Harris et al.
patent: 5754131 (1998-05-01), Ribner et al.
patent: 5789981 (1998-08-01), Singer et al.
patent: 5790062 (1998-08-01), Darnell et al.
patent: 5805093 (1998-09-01), Heikkiläet al.
patent: 5818374 (1998-10-01), Tan
patent: 5838807 (1998-11-01), Andersson et al.
patent: 5870048 (1999-02-01), Kuo et al.
patent: 5926049 (1999-07-01), Shi
patent: 6052025 (2000-04-01), Chang et al.
patent: 6081216 (2000-06-01), May
patent: 6100762 (2000-08-01), Kato
Burr-Brown Corporation, “Ultra Low Input Bias Current Instrumentation Amplifier”, ©1994 Burr-Brown Corporation, pp. 1-9.
Kasha Dan
Lee Wai Laing
Thomsen Axel
Callahan Timothy P.
Cirrus Logic Inc.
Englund Terry L.
Lin, Esq. Steven
LandOfFree
Switched capacitor integrator having very low power and low... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Switched capacitor integrator having very low power and low..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Switched capacitor integrator having very low power and low... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3024825