US4549818A
Expired / Lapsed
US
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Temperature detector
Assignee: Citizen Watch Co Ltd
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Filing: 1983-12-02
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Granted: 1985-10-29
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Expires: 2003-12-02
Abstract
Abstract A temperature detector made by a CMOS integrated circuit. The temperature detector comprises a first constant voltage circuit for producing a first constant voltage, a second constant voltage circuit applied with the first constant voltage for producing a second constant voltage, and a ring oscillator applied with the second constant voltage for producing an output voltage dependent of ambient temperature. Each constant voltage circuit has a standard resistor in the form of a diffusion resistor, a current-mirror circuit as a standard voltage generating circuit, and a voltage follower, and the ring oscillator has a delay resistor formed by a MOS transistor.
Inventors
- 👤 Yasuhiko Nishikubo
- 👤 Toyoharu Fujikawa
- 👤 Tsutomu Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:57
CPC Classifications
G; G01; G01K; G01K7/00; G01K7/16; G01K7/22; G01K7/24; G01K7/245
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
77 words
A temperature detector made by a CMOS integrated circuit, comprising: first constant voltage circuit means for producing a first constant voltage; second constant voltage circuit means, connected to said first constant voltage circuit means, applied in series with said first constant voltage for producing a second constant voltage; and ring oscillator means, connected to said first constant voltage circuit means, applied in series with said second constant voltage for producing an output voltage dependent on ambient temperature.
Claim 2
Dependent Claim
77 words
A temperature detector made by a CMOS integrated circuit, comprising: first constant voltage circuit means for producing a first constant voltage; second constant voltage circuit means, connected to said first constant voltage circuit means, applied in series with said first constant voltage for producing a second constant voltage; and ring oscillator means, connected to said first constant voltage circuit means, applied in series with said second constant voltage for producing an output voltage dependent on ambient temperature.
Claim 3
Dependent Claim
42 words
The temperature detector according to claim 1 wherein each of said first and second constant voltage circuit means has a standard resistor in the form of diffusion resistor, the difference between said first and second constant voltages being higher than 0.3 V.
Claim 4
Dependent Claim
32 words
The temperature detector according to claim 1 wherein each of said first and second constant voltage circuit means comprises a current-mirror circuit as a standard voltage generating circuit, and a voltage follower.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-10-28 | 1989-04-29 | 1989-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-28 | 1993-04-29 | 1993-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-28 | 1997-04-29 | 1997-10-29 | $7700.00 | Window Closed / Lapsed |