Patent US4916570A successfully refreshed from Google Patents.
US4916570A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Voltage comparator circuit for monitoring a process output voltage within a preset range
Assignee: Micron Technology Inc
•
Filing: 1989-05-11
•
Granted: 1990-04-10
•
Expires: 2009-05-11
Abstract
Abstract A fluctuating voltage to be monitored is fed to the non-inverting input of a first op amp via a first input resistor; a reference voltage is fed to the inverting input of the second op amp via a second input resistor. The inverting input of the first op amp is taken from a first voltage divider connected between the reference voltage and ground; the non-inverting input of the second op amp is taken from a second voltage divider connected between the fluctuating voltage and ground. The power inputs of both op amps are connected to a positive voltage and ground. The output of both op amps is tied together, with a first feedback loop feeding the tied output voltage to the non-inverting input of the first op amp via a first high-resistance gain-setting resistor, and a second feedback loop feeding the tied output voltage to the inverting input of the second op amp via a second high-resistance gain-setting resistor. The range of acceptable values for the fluctuating voltage is established by selecting appropriate resistances for the resistors which comprise the pair of voltage dividers.
Inventors
- 👤 James L. Dale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:29
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/0038
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
215 words
A voltage comparator circuit for comparing a fluctuating voltage with a stable reference voltage comprising: (a) a first operational amplifier (op amp), the non-inverting input of which is connected to said fluctuating voltage via a first input resistor, (b) a second op amp, the inverting input of which is connected to said reference voltage via a second input resistor, and the output of which is tied to the output of said first op amp; (c) a first voltage divider having a first center tap which is connected to the inverting input of said first op amp, to ground through a first grounding resistor, and to said reference voltage through a first direct connect resistor; (d) a second voltage divider having a second center tap which is connected to the non-inverting input of said second op amp, to ground through a second grounding resistor, and to said fluctuating voltage through a second direct connect resistor; (e) a first feed-back loop which routes current from the tied output of both op amps to the non-inverting input of said first op amp via a first gain-setting resistor; and (f) a second feed-back loop which routes current from the tied output of both op amps to the inverting input of said second op amp via a second gain-setting resistor.
Claim 2
Dependent Claim
215 words
A voltage comparator circuit for comparing a fluctuating voltage with a stable reference voltage comprising: (a) a first operational amplifier (op amp), the non-inverting input of which is connected to said fluctuating voltage via a first input resistor, (b) a second op amp, the inverting input of which is connected to said reference voltage via a second input resistor, and the output of which is tied to the output of said first op amp; (c) a first voltage divider having a first center tap which is connected to the inverting input of said first op amp, to ground through a first grounding resistor, and to said reference voltage through a first direct connect resistor; (d) a second voltage divider having a second center tap which is connected to the non-inverting input of said second op amp, to ground through a second grounding resistor, and to said fluctuating voltage through a second direct connect resistor; (e) a first feed-back loop which routes current from the tied output of both op amps to the non-inverting input of said first op amp via a first gain-setting resistor; and (f) a second feed-back loop which routes current from the tied output of both op amps to the inverting input of said second op amp via a second gain-setting resistor.
Claim 3
Dependent Claim
28 words
The voltage comparator circuit of claim 1 wherein both the non-inverting input and the inverting input of each op amp are connected to ground through individual noise-suppression capacitors.
Claim 4
Dependent Claim
32 words
The voltage comparator circuit of claim 2 wherein the power inputs of said first op amp and of said second op amp are connected to a positive supply voltage and to ground.
Claim 5
Dependent Claim
35 words
The voltage comparator of claim 3 wherein the ratio of said first direct-connect resistor to said first grounding resistor is essentially identical to the ratio of said second direct-connect resistor to said second grounding resistor.
Claim 6
Dependent Claim
21 words
The voltage comparator circuit of claim 4 wherein said first op amp and said second op amp are essentially identical devices.
Claim 7
Dependent Claim
19 words
The voltage comparator circuit of claim 5 wherein said first and second input resistors have essentially identical resistance values.
Claim 8
Dependent Claim
19 words
The voltage comparator circuit of claim 6 wherein said first and second gain-setting resistors have essentially identical resistance values
References Cited (Backward Citations)
US3931547A
Cited
US4835652A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-09 | 1993-10-09 | 1994-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-09 | 1997-10-09 | 1998-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-09 | 2001-10-09 | 2002-04-10 | $7700.00 | Window Closed / Lapsed |