US5477170A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Comparator capable of preventing large noise voltage
Assignee: NEC Corp
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Filing: 1994-02-17
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Granted: 1995-12-19
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Expires: 2014-02-17
Abstract
Abstract A first field effect transistor has a drain electrode connected to a first current input terminal of a first current mirror circuit and a gate electrode connected to a first voltage input terminal which is supplied with a first voltage input terminal. A second field effect transistor has a drain electrode connected to a first current output terminal of the first current mirror circuit and a gate electrode connected to a second voltage input terminal which is supplied with a second input voltage. A second current mirror circuit has a second current input terminal connected to the first current output terminal and a second current output terminal connected to a power terminal through a resistor and to a voltage output terminal which is supplied with an output voltage. A comparator may include third and fourth current mirror circuits instead of the first and the second field effect transistors. In this event, the third current mirror circuit has a third current input terminal supplied with a first input current and a third current output terminal connected to the first current input terminal. The fourth current mirror circuit has a fourth current input terminal supplied with a second input current and a fourth current output terminal connected to the first current output terminal.
Inventors
- 👤 Michio Yotsuyanagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 01:13
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/34; H03F3/343; H03F3/345; H03K; H03K5/00; H03K5/22; H03K5/24; H03K5/2472
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
218 words
A comparator having first and second voltage input terminals and a voltage output terminal, for comparing a first input voltage from said first voltage input terminal and a second input voltage from said second voltage input terminal to produce and supply an output voltage to said voltage output terminal, said comparator comprising: a first current mirror circuit having a first current input terminal and a first current output terminal; a first field-effect transistor having a first drain electrode connected to said first current input terminal, a first source electrode connected to a first power terminal, and a first gate electrode connected to said first voltage input terminal, said first power terminal supplied with a low voltage having a low level; a second field-effect transistor having a second drain electrode connected to said first current output terminal, a second source electrode connected to said first power terminal, and a second gate electrode connected to said second voltage input terminal; and a second current mirror circuit having a second current input terminal connected to said first current output terminal and a second current output terminal connected to a second power terminal through a resistor and to said voltage output terminal, said second power terminal supplied with a high voltage having a high level which is higher than said low level.
Claim 2
Dependent Claim
218 words
A comparator having first and second voltage input terminals and a voltage output terminal, for comparing a first input voltage from said first voltage input terminal and a second input voltage from said second voltage input terminal to produce and supply an output voltage to said voltage output terminal, said comparator comprising: a first current mirror circuit having a first current input terminal and a first current output terminal; a first field-effect transistor having a first drain electrode connected to said first current input terminal, a first source electrode connected to a first power terminal, and a first gate electrode connected to said first voltage input terminal, said first power terminal supplied with a low voltage having a low level; a second field-effect transistor having a second drain electrode connected to said first current output terminal, a second source electrode connected to said first power terminal, and a second gate electrode connected to said second voltage input terminal; and a second current mirror circuit having a second current input terminal connected to said first current output terminal and a second current output terminal connected to a second power terminal through a resistor and to said voltage output terminal, said second power terminal supplied with a high voltage having a high level which is higher than said low level.
Claim 3
Dependent Claim
171 words
A comparator having first and second current input terminals and a voltage output terminal, for comparing a first input current from said first current input terminal and a second input current from said second current input terminal to produce and supply an output voltage to said voltage output terminal, said comparator comprising: a first current mirror circuit having a first current output terminal and said first current input terminal; a second current mirror circuit having a second current output terminal and said second current input terminal; a third current mirror circuit having a third current input terminal connected to said first current output terminal and a third current output terminal connected to said second current output terminal; and a fourth current mirror circuit having a fourth current input terminal connected to said third current output terminal and to said second current output terminal and a fourth current output terminal connected to a power terminal through a resistor and to said voltage output terminal, said power terminal supplied with a power voltage.
Claim 4
Dependent Claim
171 words
A comparator having first and second current input terminals and a voltage output terminal, for comparing a first input current from said first current input terminal and a second input current from said second current input terminal to produce and supply an output voltage to said voltage output terminal, said comparator comprising: a first current mirror circuit having a first current output terminal and said first current input terminal; a second current mirror circuit having a second current output terminal and said second current input terminal; a third current mirror circuit having a third current input terminal connected to said first current output terminal and a third current output terminal connected to said second current output terminal; and a fourth current mirror circuit having a fourth current input terminal connected to said third current output terminal and to said second current output terminal and a fourth current output terminal connected to a power terminal through a resistor and to said voltage output terminal, said power terminal supplied with a power voltage.
Claim 5
Dependent Claim
62 words
A comparator according to claim 1, wherein said first current mirror circuit further includes a power terminal and a third field-effect transistor, said third field-effect transistor including a drain electrode coupled to said first current input terminal, a gate electrode coupled to said first current input terminal and a source electrode coupled to said power terminal of said first current mirror circuit.
Claim 6
Dependent Claim
58 words
A comparator according to claim 3, wherein said first current mirror circuit further includes a fourth field-effect transistor, said fourth field-effect transistor including a drain electrode coupled to said first current output terminal, a gate electrode coupled to said first current input terminal and a source electrode coupled to said power terminal of said first current mirror circuit.
Claim 7
Dependent Claim
62 words
A comparator according to claim 1, wherein said second current mirror circuit further includes a power terminal and a fifth field-effect transistor, said fifth field-effect transistor including a drain electrode coupled to said second current input terminal, a gate electrode coupled to said second current input terminal and a source electrode coupled to said power terminal of said second current mirror circuit.
Claim 8
Dependent Claim
58 words
A comparator according to claim 5, wherein said second current mirror circuit further includes a sixth field-effect transistor, said sixth field-effect transistor including a drain electrode coupled to said second current output terminal, a gate electrode coupled to said second current input terminal and a source electrode coupled to said power terminal of said second current mirror circuit.
Claim 9
Dependent Claim
33 words
A comparator according to claim 1, wherein said second current input terminal is coupled to a node between the first current output terminal and said second drain electrode of said second field-effect transistor.
Claim 10
Dependent Claim
28 words
A comparator according to claim 6, wherein said voltage output terminal is coupled to a node between said resistor and said drain electrode of said sixth field-effect transistor.
Claim 11
Dependent Claim
19 words
A comparator according to claim 2, wherein said first current mirror circuit further includes first and second field-effect transistors.
Claim 12
Dependent Claim
19 words
A comparator according to claim 9, wherein said second current mirror circuit further includes third and fourth field-effect transistors.
Claim 13
Dependent Claim
62 words
A comparator according to claim 2, wherein said third current mirror circuit further includes a power terminal and a fifth field-effect transistor, said fifth field-effect transistor including a drain electrode coupled to said third current input terminal, a gate electrode coupled to said third current input terminal and a source electrode coupled to said power terminal of said third current mirror circuit.
Claim 14
Dependent Claim
58 words
A comparator according to claim 11, wherein said third current mirror circuit further includes a sixth field-effect transistor, said sixth field-effect transistor including a drain electrode coupled to said third current output terminal, a gate electrode coupled to said third current input terminal and a source electrode coupled to said power terminal of said third current mirror circuit.
Claim 15
Dependent Claim
62 words
A comparator according to claim 2, wherein said fourth current mirror circuit further includes a power terminal and a seventh field-effect transistor, said seventh field-effect transistor including a drain electrode coupled to said fourth current input terminal, a gate electrode coupled to said fourth current input terminal and a source electrode coupled to said power terminal of said fourth current mirror circuit.
Claim 16
Dependent Claim
58 words
A comparator according to claim 13, wherein said fourth current mirror circuit further includes an eighth field-effect transistor, said eighth field-effect transistor including a drain electrode coupled to said fourth current output terminal, a gate electrode coupled to said fourth current input terminal and a source electrode coupled to said power terminal of said fourth current mirror circuit.
Claim 17
Dependent Claim
29 words
A comparator according to claim 2, wherein said voltage output terminal is coupled to a node between said resistor and a drain electrode of said second current mirror circuit.
Claim 18
Dependent Claim
21 words
A comparator according to claim 2, wherein input currents are caused to flow into said third and fourth current mirror circuits.
Claim 19
Dependent Claim
25 words
A comparator according to claim 2, wherein input currents are caused to flow in an inflow direction of said third and fourth current mirror circuits.
Claim 20
Dependent Claim
28 words
A comparator according to claim 2, wherein third and fourth input currents of said third and fourth current mirror circuits are caused to flow in a same direction.
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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) | 1998-12-18 | 1999-06-19 | 1999-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-12-18 | 2003-06-19 | 2003-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-12-18 | 2007-06-19 | 2007-12-19 | $7700.00 | Window Closed / Lapsed |