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US4636658A
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Voltage detecting device
Assignee: Fujitsu Ltd
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Filing: 1985-02-25
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Granted: 1987-01-13
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Expires: 2005-02-25
Abstract
Abstract A voltage detecting device including a voltage dividing circuit (VD) formed by two capacitors (C 1 ', C 2 ) connected in series, an inverter circuit (INV) for detecting whether the potential at the common node (N 1 ) of the capacitors (C 1 ', C 2 ) reaches a predetermined value, and a switching transistor (Q 3 ) linked between the common node (N 1 ) and a power supply terminal (GND). When a voltage (INP 0 ) is not applied to the voltage dividing circuit (VD), the switching transistor (Q 3 ) is turned on so as to expel the charges at the common node (N 1 ).
Inventors
- 👤 Hideki Arakawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:30
CPC Classifications
G; G01; G01R; G01R27/00; H; H03; H03K; H03K17/00; H03K17/22; G01R19/00; G01R19/165; G01R19/16504; G01R19/16519
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
115 words
A voltage detecting device comprising: first terminal means to which a detected voltage is to be applied; second terminal means; a voltage dividing circuit comprising: a first capacitor linked between said first terminal means and a common node and a second capacitor linked between the common node and said second terminal means; switching means linked between the common node and said second terminal means; a first means, connected to the common node, for generating an output signal, when the potential at the common node reaches a predetermined value; and a second means, connected to said switching means, for turning on said switching means when said detected voltage is not applied to said first terminal means.
Claim 2
Dependent Claim
115 words
A voltage detecting device comprising: first terminal means to which a detected voltage is to be applied; second terminal means; a voltage dividing circuit comprising: a first capacitor linked between said first terminal means and a common node and a second capacitor linked between the common node and said second terminal means; switching means linked between the common node and said second terminal means; a first means, connected to the common node, for generating an output signal, when the potential at the common node reaches a predetermined value; and a second means, connected to said switching means, for turning on said switching means when said detected voltage is not applied to said first terminal means.
Claim 3
Dependent Claim
39 words
A device as set forth in claim 1, wherein said first capacitor comprises a monocrystalline silicon layer, a silicon dioxide layer obtained by oxidizing said monocrystalline silicon layer, and a polycrystalline silicon layer formed on said silicon dioxide layer.
Claim 4
Dependent Claim
41 words
A device as set forth in claim 1 or 2, wherein said second capacitor comprises a monocrystalline silicon layer, a silicon dioxide layer obtained by oxidizing said monocrystalline silicon layer, and a polycrystalline silicon layer formed on said silicon dioxide layer.
Claim 5
Dependent Claim
37 words
A device as set forth in claim 1, wherein said first capacitor comprises two polycrystalline silicon layers having a silicon dioxide layer therebetween, said silicon dioxide layer being obtained by oxidizing one of said polycrystalline silicon layers.
Claim 6
Dependent Claim
37 words
A device as set forth in claim 1, wherein said second capacitor comprises two polycrystalline silicon layers having a silicon dioxide layer therebetween, said silicon dioxide layer being obtained by oxidizing one of said polycrystalline silicon layers.
Claim 7
Dependent Claim
37 words
A device as set forth in claim 4, wherein said second capacitor comprises two polycrystalline silicon layers having a silicon dioxide layer therebetween, said silicon dioxide layer being obtained by oxidizing one of said polycrystalline silicon layers.
Claim 8
Dependent Claim
18 words
A voltage detecting device as set forth in claim 1, wherein said first means comprises an inverter (INV).
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) | 1990-01-12 | 1990-07-14 | 1991-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-12 | 1994-07-14 | 1995-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-12 | 1998-07-14 | 1999-01-13 | $7700.00 | Window Closed / Lapsed |