Patent US2730863A successfully refreshed from Google Patents.
US4050031A
Expired / Lapsed
US
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Circuit and structure having high input impedance and DC return
Assignee: Signetics Corp
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Filing: 1976-03-01
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Granted: 1977-09-20
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Expires: 1996-03-01
Abstract
Abstract An amplifier circuit and structure having high input impedance and having a return path for conducting amplifier DC leakage current. A common diode structure forms the return path and includes two diodes connected in series and connected in opposite conduction directions. The diode having a forward conduction direction which is in the opposite direction of the leakage current is provided with a reverse saturation current which is substantially greater than the leakage current of the amplifier. The amplifier is typically a P channel or N channel field effect transistor (FET) and the double diode structure is typically an NPN or PNP transistor.
Inventors
- 👤 Paul R. Gray
- 👤 Mark L. Stephens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:08
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/04; H03F3/16; H03F3/165; H03F1/00; H03F1/56
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
110 words
A high impedance amplifier circuit comprising, an amplifier for receiving an input signal, said amplifier exhibiting a leakage current conducting in one direction, a leakage current conduction path connected to said amplifier for continuously biasing said amplifier and continuously providing a return for said leakage current irrespective of said input signal polarity and magnitude, said conduction path including first and second diode structures connected in series in opposite conduction directions said structures being operative independent of external fields and biasing means, one of said diode structures having a forward conduction direction opposite to said one direction and exhibiting a reverse saturation current greater than the magnitude of said leakage current.
Claim 2
Dependent Claim
110 words
A high impedance amplifier circuit comprising, an amplifier for receiving an input signal, said amplifier exhibiting a leakage current conducting in one direction, a leakage current conduction path connected to said amplifier for continuously biasing said amplifier and continuously providing a return for said leakage current irrespective of said input signal polarity and magnitude, said conduction path including first and second diode structures connected in series in opposite conduction directions said structures being operative independent of external fields and biasing means, one of said diode structures having a forward conduction direction opposite to said one direction and exhibiting a reverse saturation current greater than the magnitude of said leakage current.
Claim 3
Dependent Claim
17 words
The circuit of claim 1 wherein said first and second diode structures form an NPN transistor structure.
Claim 4
Dependent Claim
17 words
The circuit of claim 1 wherein said first and second diode structures form a PNP transistor structure.
Claim 5
Dependent Claim
13 words
The circuit of claim 1 wherein said amplifier is a field effect transistor.
Claim 6
Dependent Claim
12 words
The circuit of claim 4 wherein said transistor includes an N channel.
Claim 7
Dependent Claim
17 words
The circuit of claim 5 wherein the first and second diode structures form an NPN transistor structure.
Claim 8
Dependent Claim
17 words
The circuit of claim 5 wherein the first and second diode structures form a PNP transistor structure.
Claim 9
Dependent Claim
12 words
The circuit of claim 4 wherein said transistor includes a P channel.
Claim 10
Dependent Claim
17 words
The circuit of claim 8 wherein the first and second diode structures form an NPN transistor structure.
Claim 11
Dependent Claim
17 words
The circuit of claim 8 wherein the first and second diode structures form a PNP transistor structure.
Claim 12
Dependent Claim
19 words
The circuit of claim 1 wherein said first and second diode structures are connected in a common cathode configuration.
Claim 13
Dependent Claim
19 words
The circuit of claim 1 wherein said first and second diode structures are connected in a common anode configuration.
Claim 14
Dependent Claim
72 words
The circuit of claim 1 including, a signal generator for generating an AC signal having positive and negative excursions, capacitive means for connecting said AC signal from the signal generator as the input signal to said amplifier, wherein one of said diode structures is reverse-biased during positive excursions and where the other of said diode structures is reverse-biased during negative excursions maintaining a high impedance between said capacitive means and said amplifier.
References Cited (Backward Citations)
US3448397A
Cited
US3879640A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-19 | 1981-03-21 | 1981-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-19 | 1985-03-21 | 1985-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-19 | 1989-03-21 | 1989-09-20 | $7700.00 | Window Closed / Lapsed |