US4572977A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Range checking comparator
Assignee: Fujitsu Ltd
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Filing: 1983-12-13
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Granted: 1986-02-25
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Expires: 2003-12-13
Abstract
Abstract A comparator includes a first terminal, a second terminal, a first flip-flop circuit which inverts when the voltage applied to the first terminal becomes larger by DELTA V1 than the voltage applied to the second terminal, a third terminal, a fourth terminal, and a second flip-flop circuit which inverts when the voltage applied to the third terminal becomes smaller by DELTA V2 than the voltage applied to the fourth terminal. The comparator further includes a first switching circuit and a second switching circuit which, respectively, connect the first terminal and the fourth terminal to a voltage source to be compared, a third switching circuit and a fourth switching circuit which connect the second terminal and the third terminal to a reference voltage source. Also included is a fifth switching circuit which is commonly connected to the first flip-flop circuit and the second flip-flop circuit.
Inventors
- 👤 Yoshihiro Takemae
- 👤 Yasuo Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:26
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/353; H03K3/356; H03K3/356017; H03K3/356052; H03K3/35606
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
160 words
A comparator, comprising: a first flip-flop circuit having first and second terminals, said first flip-flop circuit changing from a first state to a second state when a voltage applied to said first terminal is larger by a first amount than a voltage applied to said second terminal; a second flip-flop circuit having third and fourth terminals, said second flip-flop circuit changing from the first state to the second state when a voltage applied to said third terminal is smaller by a second amount than a voltage applied to said fourth terminal; first and second switching circuits which, respectively, connect said first terminal and said third terminal to a common voltage source to be compared; third and fourth switching circuits which, respectively, connect said second terminal and said fourth terminal to a common reference voltage source; and a fifth switching circuit, commonly connected to said first flip-flop circuit and said second flip-flop circuit, for activating said first and second flip-flop circuits.
Claim 2
Dependent Claim
160 words
A comparator, comprising: a first flip-flop circuit having first and second terminals, said first flip-flop circuit changing from a first state to a second state when a voltage applied to said first terminal is larger by a first amount than a voltage applied to said second terminal; a second flip-flop circuit having third and fourth terminals, said second flip-flop circuit changing from the first state to the second state when a voltage applied to said third terminal is smaller by a second amount than a voltage applied to said fourth terminal; first and second switching circuits which, respectively, connect said first terminal and said third terminal to a common voltage source to be compared; third and fourth switching circuits which, respectively, connect said second terminal and said fourth terminal to a common reference voltage source; and a fifth switching circuit, commonly connected to said first flip-flop circuit and said second flip-flop circuit, for activating said first and second flip-flop circuits.
Claim 3
Dependent Claim
92 words
A comparator according to claim 1, wherein said first flip-flop circuit comprises: a first transistor having a gate connected to said second terminal; and a second transistor having a gate connected to said first terminal, wherein said second flip-flop comprises: a third transistor having a gate connected to said fourth terminal; and a fourth transistor having a gate connected to said third terminal, and wherein threshold values of said first transistor and said fourth transistor are set to be different threshold values than those of said second transistor and said third transistor.
Claim 4
Dependent Claim
100 words
A comparator according to claim 1, wherein said first flip-flop circuit comprises: a first transistor having a gate connected to said second terminal; and a second transistor having a gate connected to said first terminal, wherein said second flip-flop circuit comprises: a third transistor having a gate connected to said fourth terminal and a fourth transistor having a gate connected to said third terminal, and said comparator further comprising: a first capacitor connected to said second terminal, and to receive a phase clock pulse; and a second capacitor connected to said third terminal and to receive said phase clock pulse.
Claim 5
Dependent Claim
133 words
A comparator, comprising: a first flip-flop having first and second input terminals and a state which changes from a first state to a second state when a first voltage applied to the first terminal is larger than a common reference voltage applied to the second terminal; a second flip-flop having third and fourth input terminals and a state which changes from the first state to the second state when a second voltage applied to a third terminal is smaller than the common reference voltage applied to said fourth terminal; and means, operatively connected to said first and second flip-flops, for applying the first and second voltages as a common input voltage to be compared to said first and second flip-flops and for applying the common reference voltage to said first and second flip-flops.
Claim 6
Dependent Claim
133 words
A comparator, comprising: a first flip-flop having first and second input terminals and a state which changes from a first state to a second state when a first voltage applied to the first terminal is larger than a common reference voltage applied to the second terminal; a second flip-flop having third and fourth input terminals and a state which changes from the first state to the second state when a second voltage applied to a third terminal is smaller than the common reference voltage applied to said fourth terminal; and means, operatively connected to said first and second flip-flops, for applying the first and second voltages as a common input voltage to be compared to said first and second flip-flops and for applying the common reference voltage to said first and second flip-flops.
Claim 7
Dependent Claim
25 words
A comparator according to claim 4, further comprising activation means, operatively connected to said first and second flip-flops, for activating said first and second flip-flops.
Claim 8
Dependent Claim
23 words
A comparator according to claim 4, wherein the first and second voltages comprise a voltage range which is at least several hundred millivolts.
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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) | 1989-02-24 | 1989-08-26 | 1990-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-24 | 1993-08-26 | 1994-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-24 | 1997-08-26 | 1998-02-25 | $7700.00 | Window Closed / Lapsed |