US3781680A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential method of photocurrent measurement
Assignee: United States Department of the Air Force
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Filing: 1971-11-16
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Granted: 1973-12-25
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Expires: 1991-11-16
Abstract
Abstract A differential amplifier circuit for measuring radiation induced photocurrents in small geometry semiconductor devices.
Inventors
- 👤 W Matzen
- 👤 R Stehlin
- 👤 H Spence
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:40
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/26; G01R31/265; G01R31/2656; G01R19/00; G01R19/10
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
277 words
A differential amplifier test circuit for measuring the photocurrents which are generated within a test device operating in a simulated radiation environment comprising in combination: a differential amplifier having a first and second input terminal and a first and second output terminal, said first input terminal being connected through the device to be tested to a positive power supply voltage terminal, said first input terminal having a terminating resistor connected therebetween to ground, said second input terminal having a terminating resistor connected therebetween to ground, a first amplifier being coupled to said first output terminal of said differential amplifier, said first amplifier having an input and an output terminal, said input terminal having a terminating resistor connected therebetween to ground, said output terminal being connected to one end of a 50 ohm coax cable, said coax cable having a shield, said shield being grounded at the amplifier end, a second amplifier being coupled to said second output terminal of said differential amplifier, said second amplifier having an input and an output terminal, said input terminal having a terminating resistor connected therebetween to ground, said output terminal being connected to one end of a 50 ohm coax cable, said coax cable having a shield, said shield being grounded at the amplifier end, and, an oscilloscope having a first and second input terminal, said first input terminal being connected to the other end of said first amplifier coax cable, said first input terminal having a terminating resistor connected therebetween to ground, said second input terminal being connected to the other end of said second amplifier coax cable, said second input terminal having a terminating resistor connected therebetween to ground.
Claim 2
Dependent Claim
277 words
A differential amplifier test circuit for measuring the photocurrents which are generated within a test device operating in a simulated radiation environment comprising in combination: a differential amplifier having a first and second input terminal and a first and second output terminal, said first input terminal being connected through the device to be tested to a positive power supply voltage terminal, said first input terminal having a terminating resistor connected therebetween to ground, said second input terminal having a terminating resistor connected therebetween to ground, a first amplifier being coupled to said first output terminal of said differential amplifier, said first amplifier having an input and an output terminal, said input terminal having a terminating resistor connected therebetween to ground, said output terminal being connected to one end of a 50 ohm coax cable, said coax cable having a shield, said shield being grounded at the amplifier end, a second amplifier being coupled to said second output terminal of said differential amplifier, said second amplifier having an input and an output terminal, said input terminal having a terminating resistor connected therebetween to ground, said output terminal being connected to one end of a 50 ohm coax cable, said coax cable having a shield, said shield being grounded at the amplifier end, and, an oscilloscope having a first and second input terminal, said first input terminal being connected to the other end of said first amplifier coax cable, said first input terminal having a terminating resistor connected therebetween to ground, said second input terminal being connected to the other end of said second amplifier coax cable, said second input terminal having a terminating resistor connected therebetween to ground.
Claim 3
Dependent Claim
185 words
A differential amplifier test circuit as described in claim 1 wherein said differential amplifier comprises: a first and second transistor having their emitters connected, said first transistor base being said first input terminal, said second transistor base being said second input terminal, a constant current source connected to said emitters of said first and second transistors, said constant current source being connected to a negative power supply voltage terminal, a first emitter follower transistor having its base connected to the collector of said first transistor, said first emitter follower transistor having an emitter, said emitter having a terminating resistor connected therebetween to ground, said emitter being said first output terminal, and, a second emitter follower transistor connected to the collector of said second transistor, said second emitter follower transistor having an emitter, said emitter having a terminating resistor connected therebetween to ground, said emitter being said second output terminal, said collectors of said first and second transistors being connected to a positive power supply voltage terminal, said first and second emitter follower transistors having their respective collectors connected to said positive power supply voltage terminal.
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) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |