US3573496A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dc sense amplifier
Assignee: International Business Machines Corp
•
Filing: 1968-11-19
•
Granted: 1971-04-06
•
Expires: 1988-11-19
Abstract
Abstract This specification describes a comparator for comparing memory sense signals with a reference potential and for providing an output indicative of whether the sense signals are larger or smaller than the reference potential. The comparator includes a differential circuit that compares the output of a signal amplifier, for the sense signals, to the voltage drop across a forward biased diode. Simultaneously, the output of a model or reference amplifier, which amplifies the reference potential is compared to the diode voltage drop and the output levels of the model amplifier and the signal amplifier are simultaneously adjusted by a feedback network until the output of the model amplifier is equal to the diode voltage drop. The model and sense amplifiers are practically identical in design and are produced on the same monolithic chip so that the comparison by the differential circuit indicates whether or not the signal on the sense line exceeds the reference potential.
Inventors
- 👤 Joseph A Lake Jr
- 👤 Hannon S Yourke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:10
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/22; H03K5/24; H03K5/2409; H03K5/2418; G; G11; G11C; G11C11/00; G11C11/02; G11C11/06; G11C11/06007
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
192 words
A comparator for comparing the magnitude of signals to a reference level comprising: a. a variable gain signal amplifier having an input adapted to receive the signals and an output a function of both the signals and the gain of the amplifier; b. comparator switching means for comparing the output of the signal amplifier with a fixed level and providing a comparator output signal indicative of whether the output of the signal amplifier is larger or smaller than the fixed level; c. a variable gain reference amplifier having its input biased by the reference level and its output a function of both the reference level and the gain of the reference amplifier; and d. feedback means for adjusting the gains of both the variable gain signal amplifier and the variable gain reference amplifier to maintain at a fixed potential the potential difference between the output of the variable gain reference amplifier and the fixed level irrespective of the potential of the reference level and to cause gain of the signal amplifier to track the gain of the reference amplifier so that the gain of both amplifiers is referenced to the fixed level.
Claim 2
Dependent Claim
192 words
A comparator for comparing the magnitude of signals to a reference level comprising: a. a variable gain signal amplifier having an input adapted to receive the signals and an output a function of both the signals and the gain of the amplifier; b. comparator switching means for comparing the output of the signal amplifier with a fixed level and providing a comparator output signal indicative of whether the output of the signal amplifier is larger or smaller than the fixed level; c. a variable gain reference amplifier having its input biased by the reference level and its output a function of both the reference level and the gain of the reference amplifier; and d. feedback means for adjusting the gains of both the variable gain signal amplifier and the variable gain reference amplifier to maintain at a fixed potential the potential difference between the output of the variable gain reference amplifier and the fixed level irrespective of the potential of the reference level and to cause gain of the signal amplifier to track the gain of the reference amplifier so that the gain of both amplifiers is referenced to the fixed level.
Claim 3
Dependent Claim
146 words
The comparator of claim 1 wherein said feedback means is a voltage regulation circuit, including: a. a source of potential for driving the model and signal amplifiers; b. a first transistor with its emitter-to-collector potential coupling the source of potential to the reference and signal amplifiers; c. an output load resistor for the reference amplifier connected in series with the emitter-to-collector path of the first transistor and the source of potential; D. a second transistor with its base-to-collector path coupled across said output load resistor and the base-to-emitter path of the first transistor; e. a second resistor coupling the base of the first transistor to the source potential; and f. means coupling the emitter of the second transistor to the source of fixed potential so that the potential supplied to the reference signal amplifiers is maintained at a level that keeps the second transistor barely conducting.
Claim 4
Dependent Claim
90 words
The comparator of claim 1 wherein said comparison means is a differential current switch having two transistors connected differentially so that the transistor with the highest base potential conducts current to the exclusion of the other transistor and wherein the output of the reference amplifier is coupled to the base of the first transistor of the switch, the output of the signal amplifier is connected to the base of the second transistor of the switch and the output of the switch is taken from the collector of the second transistor.
Claim 5
Dependent Claim
39 words
The comparator of claim 3 wherein the source of current for said differential current switch comprises a differential switching means for switching current to and from said differential current switch to strobe the output of said differential current switch.
Claim 6
Dependent Claim
48 words
The comparator of claim 1 wherein said reference and signal amplifiers are each long-tailed pair differential amplifiers and include separate resistance means each coupled at one end to the collector of one of the transistors in the long-tailed pairs and to the feedback means at the other end.
Claim 7
Dependent Claim
45 words
The structure of claim 5 wherein said reference and signal amplifiers each includes an output transistor with its base coupled to the collector of one of the long-tailed pair transistors of the particular amplifier and its emitter coupled to the output of the particular amplifier.
Claim 8
Dependent Claim
47 words
The structure of claim 6 including a bias resistor coupled between a source of driving potential and the collector of said output transistor of the reference amplifier and feedback means for coupling the resistive means of the signal and reference amplifiers to the source of driving potential.
Claim 9
Dependent Claim
48 words
The structure of claim 7 wherein said feedback means includes a transistor with its collector coupled to the source of driving potential, its emitter coupled to said other end of said resistive means and its base connected to the collector of said output transistor of the reference amplifier.
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) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |