US6281747B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power efficient line driver
Assignee: Cirrus Logic Inc
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Filing: 2001-01-24
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Granted: 2001-08-28
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Expires: 2021-01-24
Abstract
Abstract A signal processing circuit is described including a frequency selective network in a feedback loop. An analog-to-analog converter in the feedback loop is coupled to the frequency selective network. A continuous-time feedback path provides feedback from the output terminal of the analog-to-analog converter to the frequency selective network.
Inventors
- 👤 Bhupendra K. Ahuja
- 👤 Cary L. Delano
- 👤 Adya S. Tripathi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:11
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/02; H03F1/0205; H03F1/0211; H03F1/0244; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/12; H03H11/1217; H03F2200/00; H03F2200/331
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
98 words
A signal processing circuit, comprising: an n th order distortion filter in a feedback loop, n being greater than one; an amplifier in the feedback loop coupled to the distortion filter, the amplifier employing one of a plurality of power supply voltages for each of a plurality of output signal ranges, the amplifier introducing nonlinearities into the feedback loop related at least in part to switching between the power supply voltages; and at least one linear, continuous-time feedback path from the amplifier to the distortion filter, the at least one continuous-time feedback path facilitating correction of the nonlinearities.
Claim 2
Dependent Claim
98 words
A signal processing circuit, comprising: an n th order distortion filter in a feedback loop, n being greater than one; an amplifier in the feedback loop coupled to the distortion filter, the amplifier employing one of a plurality of power supply voltages for each of a plurality of output signal ranges, the amplifier introducing nonlinearities into the feedback loop related at least in part to switching between the power supply voltages; and at least one linear, continuous-time feedback path from the amplifier to the distortion filter, the at least one continuous-time feedback path facilitating correction of the nonlinearities.
Claim 3
Dependent Claim
17 words
The signal processing circuit of claim 1 wherein the distortion filter comprises a plurality of integrator stages.
Claim 4
Dependent Claim
15 words
The signal processing circuit of claim 2 wherein the distortion filter comprises 2 integrator stages.
Claim 5
Dependent Claim
15 words
The signal processing circuit of claim 2 wherein the distortion filter comprises 3 integrator stages.
Claim 6
Dependent Claim
15 words
The signal processing circuit of claim 2 wherein the distortion filter comprises a Butterworth filter.
Claim 7
Dependent Claim
17 words
The signal processing circuit of claim 1 wherein the distortion filter comprises a plurality of resonator stages.
Claim 8
Dependent Claim
15 words
The signal processing circuit of claim 1 wherein the amplifier comprises a class G amplifier.
Claim 9
Dependent Claim
36 words
The signal processing circuit of claim 1 wherein the at least one continuous-time feedback path comprises a plurality of feedback elements which determine a coefficient for each of a plurality of stages of the distortion filter.
Claim 10
Dependent Claim
18 words
The signal processing circuit of claim 1 wherein the at least one continuous-time feedback path comprises scaling elements.
Claim 11
Dependent Claim
40 words
The signal processing circuit of claim 1 wherein the amplifier comprises an input terminal and an output terminal, and wherein the at least one continuous-time feedback path includes a first feedback path from the output terminal to the input terminal.
Claim 12
Dependent Claim
17 words
A line driver for a digital subscriber line comprising the signal processing circuit of claim 1 .
Claim 13
Dependent Claim
15 words
The line driver of claim 11 wherein the digital subscriber line comprises an ADSL line.
Claim 14
Dependent Claim
23 words
A method for driving a digital subscriber line comprising driving the digital subscriber line using the signal processing circuit of claim 1 .
Claim 15
Dependent Claim
12 words
An audio amplifier comprising the signal processing circuit of claim 1 .
Claim 16
Independent Claim
120 words
A method for processing a first signal using an amplifier which employs one of a plurality of power supply voltages for each of a plurality of output signal ranges, the amplifier introducing nonlinearities into the feedback loop related at least in part to switching between the power supply voltages, the method comprising: receiving the first signal with an n th order distortion filter where n is greater than one, and generating a filtered signal in response thereto; receiving the filtered signal from the frequency selective network with amplifier and generating a second signal in response thereto; and feeding the second signal back to the distortion filter via at least one linear, continuous-time feedback path, thereby facilitating correction of the nonlinearities.
Claim 17
Independent Claim
120 words
A method for processing a first signal using an amplifier which employs one of a plurality of power supply voltages for each of a plurality of output signal ranges, the amplifier introducing nonlinearities into the feedback loop related at least in part to switching between the power supply voltages, the method comprising: receiving the first signal with an n th order distortion filter where n is greater than one, and generating a filtered signal in response thereto; receiving the filtered signal from the frequency selective network with amplifier and generating a second signal in response thereto; and feeding the second signal back to the distortion filter via at least one linear, continuous-time feedback path, thereby facilitating correction of the nonlinearities.
Claim 18
Dependent Claim
13 words
The method of claim 15 wherein the first signal comprises an ADSL signal.
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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) | 2004-08-27 | 2005-02-26 | 2005-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-08-27 | 2009-02-26 | 2009-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-08-27 | 2013-02-26 | 2013-08-28 | $7700.00 | Window Closed / Lapsed |