Patent US5325071A successfully refreshed from Google Patents.
US5325071A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Operational amplifier with digitally programmable gain circuitry on the same chip
Assignee: Texas Instruments Inc
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Filing: 1993-01-15
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Granted: 1994-06-28
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Expires: 2013-01-15
Abstract
Abstract A single chip operational amplifier wherein the gain is programmable by means of a digitally controlled feedback loop wherein the parameters of the feedback circuit are digitally programmable under control of a microprocessor, microcontroller, control logic and the like. There is provided an operational amplifier with a feedback loop from output terminal to input terminal. The feedback loop contains components which are switched into the feedback loop circuit under control of digital signal provided by an external device, such as, for example, a microprocessor, microcontroller, control logic and the like. The digital signals from the external device cause the appropriate resistors and/or capacitors and/or other components, as may be required, to be switched into the feedback loop of the operational amplifier to provide the desired gain. These digital signals can be derived from a monitoring source which is designed to provide automatic gain control (AGC) or the like.
Inventors
- 👤 John C. Westmoreland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:09
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/002
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
182 words
An amplifier circuit on a single semiconductor chip which comprises: (a) a semiconductor chip having thereon each of: (i) an amplifier having an input terminal and an output terminal; (ii) a digitally operated control circuit; and (iii) a feedback circuit disposed between said input terminal and said output terminal ,said feedback circuit including a plurality of electrical circuit components, each of said circuit components having an upstream terminus and a downstream terminus, each of said circuit components having associated therewith a separate first series connected switch controlled by said control circuit and coupled to the upstream terminus of said electrical component and a separate second series connected switch controlled by said control circuit and coupled to the downstream terminus of said electrical circuit component, and a plurality of separate switches controlled by said control circuit, each of said separate switches coupled between the downstream terminus of an associated one of said circuit components and the upstream terminus of a different one of the other circuit components to provide interconnection of said circuit components on-line in one of plural serial and parallel arrangements.
Claim 2
Dependent Claim
182 words
An amplifier circuit on a single semiconductor chip which comprises: (a) a semiconductor chip having thereon each of: (i) an amplifier having an input terminal and an output terminal; (ii) a digitally operated control circuit; and (iii) a feedback circuit disposed between said input terminal and said output terminal ,said feedback circuit including a plurality of electrical circuit components, each of said circuit components having an upstream terminus and a downstream terminus, each of said circuit components having associated therewith a separate first series connected switch controlled by said control circuit and coupled to the upstream terminus of said electrical component and a separate second series connected switch controlled by said control circuit and coupled to the downstream terminus of said electrical circuit component, and a plurality of separate switches controlled by said control circuit, each of said separate switches coupled between the downstream terminus of an associated one of said circuit components and the upstream terminus of a different one of the other circuit components to provide interconnection of said circuit components on-line in one of plural serial and parallel arrangements.
Claim 3
Dependent Claim
12 words
The circuit of claim 1 wherein said amplifier is an operational amplifier.
Claim 4
Dependent Claim
16 words
The circuit of claim 2 further including an electrically resistive element coupled to said input terminal.
Claim 5
Dependent Claim
13 words
The circuit of claim 3 wherein said digitally operated control circuit is programmable.
Claim 6
Dependent Claim
13 words
The circuit of claim 2 wherein said digitally operated control circuit is programmable.
Claim 7
Dependent Claim
16 words
The circuit of claim 1 further including an electrically resistive element coupled to said input terminal.
Claim 8
Dependent Claim
13 words
The circuit of claim 6 wherein said digitally operated control circuit is programmable.
Claim 9
Dependent Claim
13 words
The circuit of claim 1 wherein said digitally operated control circuit is programmable.
References Cited (Backward Citations)
JPS5658306A
Cited
JPS5860810A
Cited
JPS5937716A
Cited
US4500845A
Cited
JPH0296413A
Cited
US5233309A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-06-27 | 1997-12-27 | 1998-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-27 | 2001-12-27 | 2002-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-27 | 2005-12-27 | 2006-06-28 | $7700.00 | Window Closed / Lapsed |