US3623132A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Charge sensing circuit
Assignee: Boeing North American Inc
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Filing: 1970-12-14
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Granted: 1971-11-23
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Expires: 1990-12-14
Abstract
Abstract A first field effect transistor is turned on during a first phase recurring interval for charging a first capacitor at the gate electrode of an output field effect transistor. During a second phase recurring interval, a second field effect transistor in series between the plate of a second capacitor and the first capacitor, is turned on. The voltage on the first capacitor is connected to the plate of the second capacitor for inverting or depleting the semiconductor region subjacent the plate of the second capacitor. If minority carriers are available in the semiconductor substrate adjacent to the region covered by the plate, the subjacent region is inverted and electrically connected to a charge coupled circuit. If an inversion does not occur, the voltage on the first capacitor is unchanged and the output field effect transistor remains on for indicating the absence of charge (minority carriers) on the charge coupled circuit. If the charge coupled circuit provides minority carriers to the second capacitor, the voltage on the first capacitor is reduced and the output field effect transistor is turned off for indicating the presence of charge on the charge coupled circuit.
Inventors
- 👤 Robert D Green
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:44
CPC Classifications
G; G11; G11C; G11C19/00; G11C19/28; G11C19/282; G11C19/285; G11C19/18; G11C19/182; G11C19/184; G11C19/186; H; H10; H10D; H10D44/00; H10D44/40; H10D44/45; H10D44/454
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
199 words
A circuit for sensing the logic state represented by the charge of a charge coupled circuit comprising, a first capacitor, a first field effect transistor charging said first capacitor to a first voltage level during a first phase recurring interval, a second capacitor means including a fixed plate disposed over and insulated from a semiconductor region, a second field effect transistor for electrically connecting said first capacitor to the fixed plate of said second capacitor means during a second phase recurring interval for inDucing an inversion layer in the semiconductor region subjacent said fixed plate if charge is provided by said charge coupled circuit, said inversion layer being electrically connected to said charge coupled circuit, if charge is not provided a depletion region is formed under said fixed plate, said charge on said first capacitor being distributed to said second capacitor means during said second phase recurring interval for changing the voltage on said first capacitor as a function of the logic state of said charge coupled circuit, output means responsive to the voltage on said first capacitor for providing an output voltage level representing the logic state of said charge coupled circuit following said second phase recurring interval.
Claim 2
Dependent Claim
199 words
A circuit for sensing the logic state represented by the charge of a charge coupled circuit comprising, a first capacitor, a first field effect transistor charging said first capacitor to a first voltage level during a first phase recurring interval, a second capacitor means including a fixed plate disposed over and insulated from a semiconductor region, a second field effect transistor for electrically connecting said first capacitor to the fixed plate of said second capacitor means during a second phase recurring interval for inDucing an inversion layer in the semiconductor region subjacent said fixed plate if charge is provided by said charge coupled circuit, said inversion layer being electrically connected to said charge coupled circuit, if charge is not provided a depletion region is formed under said fixed plate, said charge on said first capacitor being distributed to said second capacitor means during said second phase recurring interval for changing the voltage on said first capacitor as a function of the logic state of said charge coupled circuit, output means responsive to the voltage on said first capacitor for providing an output voltage level representing the logic state of said charge coupled circuit following said second phase recurring interval.
Claim 3
Dependent Claim
44 words
The circuit recited in claim 1 wherein said second field effect transistor means is connected in electrical series between said first capacitor and second capacitor means, and said first field effect transistor is connected between said first capacitor means and said first voltage level.
Claim 4
Dependent Claim
36 words
The circuit recited in claim 2 further including, a third field effect transistor for discharging charge on the fixed plate of said second capacitor means to a reference voltage level following said second phase recurring interval.
Claim 5
Dependent Claim
41 words
The circuit recited in claim 3 further including a resetting field effect device connected between the region subjacent said fixed plate and a reference voltage level for discharging said region to said reference voltage level following said second phase recurring interval.
Claim 6
Dependent Claim
53 words
The circuit recited in claim 2 wherein said second field effect transistor means is rendered nonconductive following said second phase recurring interval for isolating said first capacitor from said second capacitor means, third field effect means for connecting said second capacitor means to a reference voltage level following said second phase recurring interval.
Claim 7
Dependent Claim
89 words
The circuit recited in claim 1 wherein said output means responsive includes an output field effect transistor having its gate electrode connected to said first capacitor means for responding to the voltage on said capacitor means, said output field effect transistor being rendered nonconductive when said charge coupled circuit provides charge to said second capacitor means during said second phase recurring interval, said output field effect transistor being rendered conductive when said charge coupled circuit provides no charge to said second capacitor means during said second phase recurring interval.
Claim 8
Dependent Claim
32 words
The circuit recited in claim 6 wherein said output means comprises an inverter circuit for providing an output voltage level representing an inversion of the logic state of the charge coupled circuit.
Claim 9
Dependent Claim
29 words
The circuit recited in claim 6 wherein said output means comprises a source follower circuit for providing an uninverted output voltage representing the state of the charge coupled circuit.
Claim 10
Dependent Claim
53 words
The circuit recited in claim 1 wherein said first capacitor and second capacitor means have a ratio for reducing the voltage across said first capacitor as a function of the logic state of charge from the charge coupled circuit whereby the output means responds to the reduced voltage across said first capacitor means.
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) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |