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US4999633A
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Self-calibrating A/D and D/A converter
Assignee: Siemens AG
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Filing: 1989-09-29
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Granted: 1991-03-12
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Expires: 2009-09-29
Abstract
Abstract A self-calibrating A/D and D/A converter operating according to the principle of charge redistribution includes a weighted capacitive primary converter network for most significant bits, a subsidiary converter network for bits of lesser significance, and a calibration and correction network. Each of the networks have capacitors. A comparator has an input connected to a node point. The capacitors of the primary converter network are each connected to the node point. A coupling capacitor is connected between the capacitors of the subsidiary converter network and the node point. Another coupling capacitor is connected between the capacitors of the calibration and correction network and the node point.
Inventors
- 👤 Dieter Draxelmayr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:20
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/12; H03M1/34; H03M1/38; H03M1/46; H03M1/466; H03M1/10; H03M1/1009; H03M1/1033; H03M1/1038; H03M1/1047; H03M1/66; H03M1/68; H03M1/74; H03M1/80; H03M1/802; H03M1/804
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
105 words
Self-calibrating A/D and D/A converter operating according to the principle of charge redistribution, comprising a weighted capacitive primary converter network for most significant bits, a subsidiary converter network for bits of lesser significance, a calibration and correction network, each of said networks having capacitors, a node point, a comparator having an input connected to said node point, said capacitors of said primary converter network each being connected to said node point, a coupling capacitor connected between said capacitors of said subsidiary converter network and said node point, and another coupling capacitor connected between said capacitors of said calibration and correction network and said node point.
Claim 2
Dependent Claim
105 words
Self-calibrating A/D and D/A converter operating according to the principle of charge redistribution, comprising a weighted capacitive primary converter network for most significant bits, a subsidiary converter network for bits of lesser significance, a calibration and correction network, each of said networks having capacitors, a node point, a comparator having an input connected to said node point, said capacitors of said primary converter network each being connected to said node point, a coupling capacitor connected between said capacitors of said subsidiary converter network and said node point, and another coupling capacitor connected between said capacitors of said calibration and correction network and said node point.
Claim 3
Dependent Claim
48 words
Converter according to claim 1, wherein said capacitors of said networks are binary weighting capacitors having capacitances being independent of one another, said capacitors of each of said networks include a smallest weighting capacitor, and said smallest weighting capacitor of said subsidiary converter network is provided in duplicate.
Claim 4
Dependent Claim
28 words
Converter according to claim 2, wherein said subsidiary converter network includes a correction capacitor for the least significant bit corresponding in value to one-half said smallest weighting capacitor.
Claim 5
Dependent Claim
44 words
Converter according to claim 2, wherein the number of weighting capacitors in said converter networks depends on the bit resolution of the converter, and said primary converter network includes a number of weighting capacitors at least equal to that of said subsidiary converter network.
Claim 6
Dependent Claim
32 words
Converter according to claim 2, wherein said smallest weighting capacitor of said subsidiary converter network is equivalent to approximately twice the value of said smallest weighting capacitor of said primary converter network.
Claim 7
Dependent Claim
18 words
Converter according to claim 2, wherein said calibration and correction network includes a variable number of weighting capacitors.
Claim 8
Dependent Claim
27 words
Converter according to claim 2, wherein said calibration and correction network includes a number of weighting capacitors equivalent to approximately one-half the bit resolution of the converter.
Claim 9
Dependent Claim
31 words
Converter according to claim 2, wherein said smallest weighting capacitor of said calibration and correction network is approximately half as large as said smallest weighting capacitor of said primary converter network.
Claim 10
Dependent Claim
44 words
Converter according to claim 2, wherein said coupling capacitor connected between said capacitors of said subsidiary converter network and said node point has a capacitance equivalent to between 1 and 1.4 times the value of said smallest weighting capacitor of said primary converter network.
Claim 11
Dependent Claim
45 words
Converter according to claim 2, wherein said coupling capacitor connected between said capacitors of said calibration and correction network and said node point has a capacitance equivalent to between 0.1 and 1 times the value of said smallest weighting capacitor of said primary converter network.
References Cited (Backward Citations)
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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) | 1994-03-11 | 1994-09-10 | 1995-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-03-11 | 1998-09-10 | 1999-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-03-11 | 2002-09-10 | 2003-03-12 | $7700.00 | Window Closed / Lapsed |