Patent US4613768A successfully refreshed from Google Patents.
US4613768A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature dependent, voltage reference comparator/diode
Assignee: AG Communication Systems Corp
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Filing: 1984-11-13
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Granted: 1986-09-23
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Expires: 2004-11-13
Abstract
Abstract A precise temperature dependent voltage reference and voltage comparator comprising a three terminal circuit. When the input voltage exceeds a predetermined threshold, the output switches from the nonconducting, "off" state to a current conducting "on" state. The threshold condition can be tailored to a specific temperature characteristic and low voltage range with an input current on the order of 25 microamperes. With the output tied to the input, the circuitry can act as a reference diode.
Inventors
- 👤 II Karl E. Pommer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:34
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/14; H03K17/30
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
126 words
A combined temperature dependent voltage reference and voltage comparator circuit comprising: an input; a current source comprising the base-emitter diode of a first transistor, and adjustable resistance means connected between said input and said first transistor base; voltage reference means comprising a temperature dependent voltage reference including first and second oppositely poled unidirectional conducting means connected to said first transistor base by means of a variable resistance; a differential voltage detector including a portion of said current source; output means; and current amplifier means connected between said voltage detector and said output means; said circuit operated in response to a voltage applied to said input being equal to a predetermined threshold voltage, to cause said detector to initiate the conduction of current through said output means.
Claim 2
Dependent Claim
126 words
A combined temperature dependent voltage reference and voltage comparator circuit comprising: an input; a current source comprising the base-emitter diode of a first transistor, and adjustable resistance means connected between said input and said first transistor base; voltage reference means comprising a temperature dependent voltage reference including first and second oppositely poled unidirectional conducting means connected to said first transistor base by means of a variable resistance; a differential voltage detector including a portion of said current source; output means; and current amplifier means connected between said voltage detector and said output means; said circuit operated in response to a voltage applied to said input being equal to a predetermined threshold voltage, to cause said detector to initiate the conduction of current through said output means.
Claim 3
Dependent Claim
24 words
A combined temperature dependent voltage reference and voltage comparator circuit as claimed in claim 1 wherein: said differential voltage detector comprises said first transistor.
Claim 4
Dependent Claim
24 words
A combined temperature dependent voltage reference and voltage comparator circuit as claimed in claim 2 wherein said first transistor is of the PNP type.
Claim 5
Dependent Claim
31 words
A combined temperature dependent voltage reference and voltage comparator circuit as claimed in claim 1 wherein: said output means comprise an output terminal connected to the collector of a second transistor.
Claim 6
Dependent Claim
24 words
A combined temperature dependent voltage reference and voltage comparator circuit as claimed in claim 4 wherein: said second transistor is of the NPN type.
Claim 7
Dependent Claim
24 words
A combined temperature dependent voltage reference and voltage comparator circuit as claimed in claim 4 wherein: said current amplifier means comprises a third transistor.
Claim 8
Dependent Claim
24 words
A combined temperature dependent voltage reference and voltage comparator circuit as claimed in claim 6 wherein: said third transistor is of the NPN type.
Claim 9
Dependent Claim
31 words
A combined temperature dependent voltage reference and voltage comparator circuit as claimed in claim 1 wherein: there is further included base current limiting means including circuit connections to said first transistor.
Claim 10
Dependent Claim
37 words
A combined temperature dependent voltage reference and voltage comparator circuit as claimed in claim 1 wherein: there is further included leakage current limiting means including circuit connections to said output means and to said current amplifier 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) | 1989-09-22 | 1990-03-24 | 1990-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-22 | 1994-03-24 | 1994-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-22 | 1998-03-24 | 1998-09-23 | $7700.00 | Window Closed / Lapsed |