US4868418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Comparator circuit using resonant-tunneling transistor
Assignee: Fujitsu Ltd
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Filing: 1988-02-03
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Granted: 1989-09-19
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Expires: 2008-02-03
Abstract
Abstract A comparator circuit comprises a differential amplifier supplied with a reference signal and an input signal. A resonant-tunneling transistor has a base supplied with an output signal of the differential amplifier. A collector is connected to a first power supply source via a resistor. An emitter is connected to a second power supply source. Therefore, it is possible to simplify a circuit configuration of the comparator circuit and to improve an operation speed of the comparator circuit by outputting an output signal from a connection portion between the resistor and the collector of the transistor.
Inventors
- 👤 Kenichi Imamura
- 👤 Masao Taguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:02
CPC Classifications
B; B82; B82Y; B82Y10/00; H; H03; H03K; H03K5/00; H03K5/22; H03K5/24; H03K5/2409; H03K5/2418
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
108 words
A comparator circuit comprising: a first power supply means; a second power supply means; a resistor means connected to said first power supply means; a differential amplifier supplied with a reference signal and an input signal; a resonant-tunneling transistor having a base connected to said differential amplifier for receiving an output signal of said differential amplifier, a collector connected to said first power supply means via said resistor means, and an emitter connected to said second power supply means; and an output terminal connected to a connection portion between said collector of said resonant-tunneling transistor and said resistor means, for outputting an output signal of said comparator circuit.
Claim 2
Dependent Claim
108 words
A comparator circuit comprising: a first power supply means; a second power supply means; a resistor means connected to said first power supply means; a differential amplifier supplied with a reference signal and an input signal; a resonant-tunneling transistor having a base connected to said differential amplifier for receiving an output signal of said differential amplifier, a collector connected to said first power supply means via said resistor means, and an emitter connected to said second power supply means; and an output terminal connected to a connection portion between said collector of said resonant-tunneling transistor and said resistor means, for outputting an output signal of said comparator circuit.
Claim 3
Dependent Claim
17 words
A comparator circuit as claimed in claim 1, wherein said resonant-tunneling transistor comprises a resonant-tunneling hot-electron transistor.
Claim 4
Dependent Claim
17 words
A comparator circuit as claimed in claim 1, wherein said resonant-tunneling transistor comprises a resonant-tunneling bipolar transistor.
Claim 5
Dependent Claim
16 words
A comparator circuit as claimed in claim 1, wherein said resonant-tunneling transistor comprises a GaAs/AlGaAs heterostructure.
Claim 6
Dependent Claim
16 words
A comparator circuit as claimed in claim 1, wherein said resonant-tunneling transistor comprises a GaInAs/(AlGa)InAs heterostructure.
Claim 7
Dependent Claim
23 words
A comparator circuit as claimed in claim 1, wherein said differential amplifier comprises transistors which are the same type as said resonant-tunneling transistor.
Claim 8
Dependent Claim
24 words
A comparator circuit as claimed in claim 1, wherein said resistor means is made of metal silicide or metal nitride by a sputtering method.
Claim 9
Dependent Claim
15 words
A comparator circuit as claimed in claim 1, which is used as an analog-to-digital converter.
Claim 10
Dependent Claim
58 words
A comparator circuit as claimed in claim 1, wherein said resonant-tunneling transistor has a characteristic curve including a peak and a valley in the collector current against a base-emitter voltage, and said differential amplifier outputs a high level signal close to a voltage of said valley and a low level signal close to a voltage of said peak.
Claim 11
Dependent Claim
23 words
A comparator circuit as claimed in claim 9, wherein the voltage of said valley is almost equal to the voltage of said peak.
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) | 1992-09-18 | 1993-03-20 | 1993-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-18 | 1997-03-20 | 1997-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-18 | 2001-03-20 | 2001-09-19 | $7700.00 | Window Closed / Lapsed |