Patent US3787776A successfully refreshed from Google Patents.
US3787776A
Expired / Lapsed
US
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High speed current amplifier
Assignee: Keithley Instruments LLC
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Filing: 1971-10-06
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Granted: 1974-01-22
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Expires: 1991-10-06
Abstract
Abstract A high speed current amplifier is disclosed for purposes of amplifying current signals from a current source over a wide frequency band while minimizing generated noise. The amplifier employs amplifying circuitry having an input adapted to be connected to a current source and an output, with the amplifying circuitry exhibiting an open loop gain of A. A resistive feedback path is employed, which exhibits a resistance R, connected between the input and output so that the amplifying circuitry would normally exhibit a useful band width extending to roll-off frequency F1 where F1 A/(2 pi RC), with C being the shunt capacitance across the amplifier input. An attenuator is connected to the output of the amplifier for purposes of attenuating high frequency noise components above frequency F2, where F2 is less than frequency F1 and at a rate greater than that of a single roll-off.
Inventors
- 👤 P Cath
- 👤 G Angeline
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:23
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/26; G; G01; G01R; G01R19/00; G01R19/0092
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
152 words
A high speed current amplifier for amplifying current signals from a current source over a wide frequency band while minimizing noise, and comprising: amplifying means having an input adapted to be connected to a said source and an output and exhibiting an open loop gain of A, a resistive feedback path exhibiting a resistance R connected between said input and said output so that said amplifying means would normally exhibit a useful band width extending to a roll-off frequency F1, where: F1 A/(2 pi RC) and C is the shunt capacitance across said input, attenuating means connected to said output for attenuating high frequency noise components above frequency F2, where F2 is less than F1 and at a rate greater than six decibels per frequency octave, and comparing means for comparing the output signal from said attenuating means with a reference signal and providiNg an output indication in dependence upon said comparison.
Claim 2
Dependent Claim
152 words
A high speed current amplifier for amplifying current signals from a current source over a wide frequency band while minimizing noise, and comprising: amplifying means having an input adapted to be connected to a said source and an output and exhibiting an open loop gain of A, a resistive feedback path exhibiting a resistance R connected between said input and said output so that said amplifying means would normally exhibit a useful band width extending to a roll-off frequency F1, where: F1 A/(2 pi RC) and C is the shunt capacitance across said input, attenuating means connected to said output for attenuating high frequency noise components above frequency F2, where F2 is less than F1 and at a rate greater than six decibels per frequency octave, and comparing means for comparing the output signal from said attenuating means with a reference signal and providiNg an output indication in dependence upon said comparison.
Claim 3
Dependent Claim
172 words
A high speed current amplifier for amplifying current signals from a current source over a wide frequency band while minimizing noise, and comprising: amplifying means having an input adapted to be connected to a said source and an output and exhibiting an open loop gain of A, a resistive feedback path exhibiting a resistance R connected between said input and said output so that said amplifying means would normally exhibit a useful band width extending to a roll-off frequency F1, where: F1 A/(2 pi RC) and C is the shunt capacitance across said input, attenuating means connected to said output for attenuating high frequency noise components above frequency F2, where F2 is less than F1 and at a rate greater than six decibels per frequency octave, and dual comparator means for comparing both the input signal to said attenuating means with a reference signal as well as the output signal of said attenuating means with a reference signal and providing an output indication in dependence upon at least one of said comparisons.
Claim 4
Dependent Claim
172 words
A high speed current amplifier for amplifying current signals from a current source over a wide frequency band while minimizing noise, and comprising: amplifying means having an input adapted to be connected to a said source and an output and exhibiting an open loop gain of A, a resistive feedback path exhibiting a resistance R connected between said input and said output so that said amplifying means would normally exhibit a useful band width extending to a roll-off frequency F1, where: F1 A/(2 pi RC) and C is the shunt capacitance across said input, attenuating means connected to said output for attenuating high frequency noise components above frequency F2, where F2 is less than F1 and at a rate greater than six decibels per frequency octave, and dual comparator means for comparing both the input signal to said attenuating means with a reference signal as well as the output signal of said attenuating means with a reference signal and providing an output indication in dependence upon at least one of said comparisons.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |