US4177394A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Comparator circuit having multi-functions
Assignee: Hitachi Ltd
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Filing: 1977-08-29
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Granted: 1979-12-04
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Expires: 1997-08-29
Abstract
Abstract A comparator circuit comprises first and second transistors having bases for receiving first and second input voltages, respectively, and a third transistor having a base for receiving a third input voltage to be compared with the first and second input voltages. The first, second and third transistors have respective emitters connected in common to a constant current source. Switching means is provided for selectively supplying a potential to the base of the first transistor thereby to turn off the same and is connected to a switch control means, to produce the collector potential of the third transistor or a corresponding potential.
Inventors
- 👤 Wasao Takasugi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:24
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/22; H03K5/24
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
152 words
A comparator circuit comprising: first and second transistors having respective input electrodes for receiving first and second input signals, respectively; a third transistor having an input electrode for receiving a third input signal to be compared with said first and second input signals; input means connected to the respective input electrodes of said first, second and third transistors for supplying said first, second and third input signals; a current source connected in common to said first output electrodes of said first, second and third transistors; a first control means connected to the input electrode of said first transistor and responsive to a control signal for selectively rendering said first transistor non-conductive independent of said first input signal; potential source means connected to second output electrodes of said first, second and third transistors; and output means connected to the second output electrode of at least one of said first, second and third transistors.
Claim 2
Dependent Claim
152 words
A comparator circuit comprising: first and second transistors having respective input electrodes for receiving first and second input signals, respectively; a third transistor having an input electrode for receiving a third input signal to be compared with said first and second input signals; input means connected to the respective input electrodes of said first, second and third transistors for supplying said first, second and third input signals; a current source connected in common to said first output electrodes of said first, second and third transistors; a first control means connected to the input electrode of said first transistor and responsive to a control signal for selectively rendering said first transistor non-conductive independent of said first input signal; potential source means connected to second output electrodes of said first, second and third transistors; and output means connected to the second output electrode of at least one of said first, second and third transistors.
Claim 3
Dependent Claim
29 words
A comparator circuit as set forth in claim 1, wherein said first control means comprises a switching means for selectively supplying a potential for making said first transistor non-conductive.
Claim 4
Dependent Claim
34 words
A comparator circuit as set forth in claim 2, wherein said switching means comprises a fourth transistor having an input electrode for receiving said control signal in the form of a fourth input signal.
Claim 5
Dependent Claim
30 words
A comparator circuit as set forth in claim 1, further including load means connected between second output electrodes of said first, second and third transistors and said potential source means.
Claim 6
Dependent Claim
24 words
A comparator circuit as set forth in claim 1, wherein said output means is connected to the second output electrode of said third transistor.
Claim 7
Dependent Claim
74 words
A comparator circuit as set forth in claim 4, wherein the second output electrodes of said first and second transistors are connected in common and said load means comprises a first load element connected between the common connection of the second output electrodes of said first and second transistors and said potential source means, and a second load element connected between the second output electrode of said third transistor and said potential source means.
Claim 8
Dependent Claim
42 words
A comparator circuit as set forth in claim 1, further comprising second control means connected to the input electrode of said second transistor and responsive to a second control signal for making said second transistor non-conductive independent of said second input signal.
Claim 9
Dependent Claim
29 words
A comparator circuit as set forth in claim 7, wherein said second control means comprise a switching means for selectively supplying a potential for making said second transistor non-conductive.
Claim 10
Dependent Claim
28 words
A comparator circuit as set forth in claim 1, further including feedback means for feeding the output signal from said output means back to said first control means.
Claim 11
Dependent Claim
87 words
A comparator circuit as set forth in claim 7, further including a fourth transistor having an input electrode for receiving a fourth input signal to be compared with said first and second input signals, a fourth control means connected to the input electrode of said fourth transistor and responsive to a fourth control signal for making said fourth transistor non-conductive, and a third control means connected to the input electrode of said third transistor and responsive to a third control signal for making said third transistor non-conductive.
Claim 12
Dependent Claim
36 words
A comparator circuit as set forth in claim 10, said first, second, third and fourth control means comprise, respectively, switching means for selectively supplying potentials for making non-conductive the associated first, second, third and fourth transistors.
Claim 13
Dependent Claim
28 words
A comparator circuit as set forth in claim 1, wherein said first and second input signals are reference signals having a high level and a low level, respectively.
Claim 14
Dependent Claim
24 words
A comparator circuit as set forth in claim 12, wherein said output means is connected to the second output electrode of said third transistor.
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) | 1982-12-03 | 1983-06-04 | 1983-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-03 | 1987-06-04 | 1987-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-03 | 1991-06-04 | 1991-12-04 | $7700.00 | Window Closed / Lapsed |