US3649846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single supply comparison amplifier
Assignee: Motorola Solutions Inc
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Filing: 1971-01-07
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Granted: 1972-03-14
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Expires: 1991-01-07
Abstract
Abstract A monolithic integrated circuit comparison amplifier employs Darlington and modified Darlington connected PNP transistors in a differential circuit configuration to compare input voltages having a common-mode voltage range extending down to 0 volts. The comparison amplifier operates from a single voltage supply.
Inventors
- 👤 Thomas M Frederiksen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:34
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/22; H03K5/24; H03K5/2409; H03K5/2418
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
262 words
A comparison circuit including in combination: first and second voltage supply terminals, one of said supply terminals for connection with a source of DC operating potential and the other of said supply terminals for connection with a point of reference potential; first and second transistors of the same conductivity type, each having a collector, base, and emitter; first circuit means connecting said first supply terminal with the emitters of said first and second transistors; third and fourth transistors of said same conductivity type as said first and second transistors, said third and fourth transistors each having a collector, base, and emitter; means coupling the emitters of said third and fourth transistors with the bases of said first and second transistors respectively; semiconductor means comprising diode means coupling the collector of said first transistor with said second supply terminal and comprising fifth transistor means of opposite conductivity type to the conductivity type of said first, second, third and fourth transistors and having a collector, base and emitter, the collector of said fifth transistor means being connected with the collector of said second transistor, the emitter of said fifth transistor means being connected with second supply terminal, and the base of said fifth transistor means being connected with the collector of said first transistor; further circuit means coupling the collectors of said third and fourth transistors with said second supply terminal; first input means for applying a first input signal to the base of said third transistor; and second input means for applying a second input signal to the base of said fourth transistor.
Claim 2
Dependent Claim
262 words
A comparison circuit including in combination: first and second voltage supply terminals, one of said supply terminals for connection with a source of DC operating potential and the other of said supply terminals for connection with a point of reference potential; first and second transistors of the same conductivity type, each having a collector, base, and emitter; first circuit means connecting said first supply terminal with the emitters of said first and second transistors; third and fourth transistors of said same conductivity type as said first and second transistors, said third and fourth transistors each having a collector, base, and emitter; means coupling the emitters of said third and fourth transistors with the bases of said first and second transistors respectively; semiconductor means comprising diode means coupling the collector of said first transistor with said second supply terminal and comprising fifth transistor means of opposite conductivity type to the conductivity type of said first, second, third and fourth transistors and having a collector, base and emitter, the collector of said fifth transistor means being connected with the collector of said second transistor, the emitter of said fifth transistor means being connected with second supply terminal, and the base of said fifth transistor means being connected with the collector of said first transistor; further circuit means coupling the collectors of said third and fourth transistors with said second supply terminal; first input means for applying a first input signal to the base of said third transistor; and second input means for applying a second input signal to the base of said fourth transistor.
Claim 3
Dependent Claim
72 words
The combination according to claim 1 wherein said diode means comprises a diode connected between the collector of said first transistor and said second supply terminal and said fifth transistor means comprises a transistor, the collector of which is connected to the collector of said second transistor the emitter of which is connected to said second supply terminal, and the base of which is connected to thE collector of said first transistor.
Claim 4
Dependent Claim
44 words
The combination according to claim 1 wherein said first, second, third and fourth transistors all are PNP transistors and said first supply terminal is adapted for connection with a positive source of DC operating potential and said second supply terminal is connected to ground.
Claim 5
Dependent Claim
46 words
The combination according to claim 1 wherein the comparison circuit is a monolithic integrated circuit and said first, second, third and fourth transistors are PNP transistors, with at least said second transistor being a lateral PNP transistor, and said fifth transistor means is an NPN transistor.
Claim 6
Dependent Claim
73 words
The combination according to claim 1 further including a sixth transistor of the same conductivity type as said fifth transistor means and having a collector, base, and emitter, the base of said sixth transistor being connected to the collector of said fifth transistor means, the emitter of said sixth transistor being connected with said second voltage supply terminal, and the collector of said sixth transistor comprising an output terminal for the comparison circuit.
Claim 7
Dependent Claim
63 words
The combination according to claim 1 wherein said one voltage supply terminal is adapted for connection with a positive source of DC operating potential, said first circuit means is a current source, one of said first and second input means applies a DC reference input signal and the other of said first and second input means applies a time varying input signal level.
Claim 8
Dependent Claim
76 words
The combination according to claim 6 wherein said first input means applies the reference input signal and said second input means applies the time varying input signal level, and said second input means includes a charging circuit and storage capacitor connected together at a junction and in series in the order named between said one voltage supply terminal and said point of reference potential, with said junction being connected to the base of said third transistor.
Claim 9
Dependent Claim
261 words
A monolithic integrated comparison circuit including in combination: first and second voltage supply terminals, one of said supply terminals for a connection with a source of DC operating potential and the other of said supply terminals for connection with a point of reference potential; first and second transistors of the same conductivity type, each having a collector, base, and emitter; first circuit means connecting said first supply terminal with the emitters of said first and second transistors; third and fourth transistors of said same conductivity type as said first and second transistors, said third and fourth transistors each having a collector, base, and emitter; means coupling the emitters of said third and fourth transistors with the bases of said first and second transistors respectively; pinch resistor means coupling the collector of said second transistor with said second voltage supply terminal; further circuit means coupling the collectors of said first, third and fourth transistors with said second supply terminal; a fifth transistor of opposite conductivity type to the conductivity type of said first, second, third and fourth transistors and having a collector, base, and emitter, the base of said fifth transistor being connected to the collector of said second transistor, the emitter of said fifth transistor being connected with said second voltage supply terminal, and the collector of said fifth transistor comprising an output terminal for the comparison circuit; first input means for applying a first input signal to the base of said third transistor; and second input means for applying a second input signal to the base of said fourth transistor.
Claim 10
Dependent Claim
261 words
A monolithic integrated comparison circuit including in combination: first and second voltage supply terminals, one of said supply terminals for a connection with a source of DC operating potential and the other of said supply terminals for connection with a point of reference potential; first and second transistors of the same conductivity type, each having a collector, base, and emitter; first circuit means connecting said first supply terminal with the emitters of said first and second transistors; third and fourth transistors of said same conductivity type as said first and second transistors, said third and fourth transistors each having a collector, base, and emitter; means coupling the emitters of said third and fourth transistors with the bases of said first and second transistors respectively; pinch resistor means coupling the collector of said second transistor with said second voltage supply terminal; further circuit means coupling the collectors of said first, third and fourth transistors with said second supply terminal; a fifth transistor of opposite conductivity type to the conductivity type of said first, second, third and fourth transistors and having a collector, base, and emitter, the base of said fifth transistor being connected to the collector of said second transistor, the emitter of said fifth transistor being connected with said second voltage supply terminal, and the collector of said fifth transistor comprising an output terminal for the comparison circuit; first input means for applying a first input signal to the base of said third transistor; and second input means for applying a second input signal to the base of said fourth transistor.
Claim 11
Dependent Claim
25 words
The combination according to claim 9 wherein the collectors of the first, third and fourth transistors are connected directly with said point of reference potential.
Claim 12
Dependent Claim
36 words
The combination according to claim 9 wherein said first, second, third and fourth transistors are PNP transistors, with at least said second transistor being a lateral PNP transistor and said fifth transistor is an NPN transistor.
Claim 13
Dependent Claim
26 words
The combination according to claim 11 wherein said first and second transistors are lateral PNP transistors and said third and fourth transistors are substrate PNP transistors.
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) | 1975-03-14 | 1975-09-13 | 1976-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-14 | 1979-09-13 | 1980-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-14 | 1983-09-13 | 1984-03-14 | $7700.00 | Window Closed / Lapsed |