Patent US4749953A successfully refreshed from Google Patents.
US4749953A
Expired / Lapsed
US
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Operational amplifier or comparator circuit with minimized offset voltage and drift
Assignee: Individual
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Filing: 1986-12-24
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Granted: 1988-06-07
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Expires: 2006-12-24
Abstract
Abstract The invention relates to an operational amplifier (OA) or comparator circuit with minimized offset voltage and drift, particularly for analog and/or digital systems requiring high speed and high accuracy signal processing, such as integrators, analog-to-digital converters, etc. The provided OA and comparators circuits retain a high speed and have a drastically increased accuracy. No correcting amplifier is necessary. The gain set by external components is insignificant. Widely available high speed switching components can be used. The tolerance of the passive components used is not critical. The values of the capacitors are determined by the switching frequency and amount of the input bias current of the employed OA. A FET OA can be used as its very large offset voltage and drift can be easily compensated.
Inventors
- 👤 Zdzislaw Gulczynski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:31
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/30; H03F1/303
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
59 words
An amplifier circuit, comprising: an amplifier means having a pair of inputs and exhibiting an error voltage therebetween; means for coupling an input signal to the inputs and including capacitor means coupled in series between the input signal and one of the inputs for storing the error voltage; and means for applying the error voltage across the capacitor means.
Claim 2
Dependent Claim
59 words
An amplifier circuit, comprising: an amplifier means having a pair of inputs and exhibiting an error voltage therebetween; means for coupling an input signal to the inputs and including capacitor means coupled in series between the input signal and one of the inputs for storing the error voltage; and means for applying the error voltage across the capacitor means.
Claim 3
Dependent Claim
40 words
Amplifier circuit of claim 1, wherein the means for applying includes means for coupling the capacitor means across the inputs and means for alternately coupling the input signal to the inputs while the capacitor means is coupled across the inputs.
Claim 4
Dependent Claim
35 words
Amplifier circuit of claim 2, wherein the means for coupling includes a pair of input terminals for receiving the input signal with one of the input terminals connected to one of the amplifier means inputs.
Claim 5
Dependent Claim
83 words
Amplifier circuit of claim 3, wherein the capacitor means includes a first end connected to the other amplifier means input and a second end, and further wherein the means for applying includes a first switch for alternately connecting the second end of the capacitor means to either the other input terminal or the one input terminal, and a second switch for connecting the other amplifier means input to the other input terminal while the first switch is connected to the one input terminal.
Claim 6
Dependent Claim
70 words
Amplifier circuit of claim 3, wherein the capacitor means includes a first end connected to the other amplifier means input and a second end, and further wherein the means for applying includes a first switch for alternately connecting the second end of the capacitor means to either the other input terminal or the one input terminal, and a capacitor coupling the other amplifier means input to the other input terminal.
Claim 7
Dependent Claim
19 words
Amplifier circuit of claim 4, wherein the capacitor means includes a second capacitor connected in series with a resistor.
Claim 8
Dependent Claim
54 words
Amplifier circuit of claim 1, wherein the amplifier means has an output and one of the pair of inputs is an inverting input, and further wherein the means for applying includes means for coupling the inverting input to the output and means for coupling the capacitor means from the other input to the output.
Claim 9
Dependent Claim
83 words
Amplifier circuit of claim 7, wherein the capacitor means includes a first end connected to the other amplifier means input and a second end, and further wherein the means for applying includes a first swtich for alternately connecting the second end of the capacitor means to either the other input terminal or the amplifier means output, and a second switch for connecting the other amplifier means input to the other input terminal while the first switch is connected to the amplifier means output.
Claim 10
Dependent Claim
70 words
Amplifier circuit of claim 7, wherein the capacitor means includes a first end connected to the other amplifier means input and a second end, and further wherein the means for applying includes a first switch for alternately connecting the second end of the capacitor means to either the other input terminal or the one input terminal, and a capacitor coupling the other amplifier means input to the other input terminal.
Claim 11
Dependent Claim
19 words
Amplifier circuit of claim 9, wherein the capacitor means includes a second capacitor connected in series with a resistor.
Claim 12
Dependent Claim
13 words
Amplifier circuit of claim 1, wherein the amplifier means is an operational amplifier.
Claim 13
Dependent Claim
12 words
Amplifier circuit of claim 1, wherein the amplifier means is a comparator.
Claim 14
Dependent Claim
36 words
Amplifier circuit of claim 1, wherein the means for applying includes a second capacitor means and means for coupling the second capacitor means alternately across the amplifier means inputs and across the first said capacitor means.
Claim 15
Dependent Claim
74 words
Amplifier circuit of claim 13, wherein the second capacitor means includes a capacitor connected in series with a resistor and having one end coupled to the one of the amplifier means inputs, and further wherein the means for coupling the second capacitor means includes a switch connected to the other end thereof for alternately connecting the second capacitor means either across the amplifier means inputs or in parallel with the first said capacitor means.
References Cited (Backward Citations)
US4439693A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-07 | 1991-12-07 | 1992-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-07 | 1995-12-07 | 1996-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-07 | 1999-12-07 | 2000-06-07 | $7700.00 | Window Closed / Lapsed |