US4070667A
Expired / Lapsed
US
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Charge transfer analog-to-digital converter
Assignee: General Electric Co
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Filing: 1975-11-03
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Granted: 1978-01-24
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Expires: 1995-11-03
Abstract
Abstract A charge transfer analog-to-digital converter is described wherein an analog signal is converted to a digital equivalent thereof in a structure suitable to be implemented in MOS form. A dual slope technique is employed wherein the digital output is the ratio between the input signal and a reference signal.
Inventors
- 👤 Charles W. Eichelberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:55
CPC Classifications
H; H10; H10D; H10D44/00; H10D44/40; H10D44/45; H03; H03M; H03M1/00; H03M1/12; H03M1/34; H03M1/38; H03M1/44
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
170 words
An analog to digital converter comprising: a first charge storage location; means for establishing a first charge level in said first charge storage location; means for removing a first metered plurality of charge packets from said first charge storage location, the size of the charge packets in said first plurality of charge packets being proportional to the magnitude of a first input signal; means for adding a second metered plurality of charge packets to said first charge storage location, the size of the charge packets in said second plurality proportional to the magnitude of a first reference voltage; and means for detecting the presence of said first charge level in said first charge storage location and providing an output signal in response thereto; the ratio between the number of charge packets in said first plurality to the number of charge packets in said second plurality at the time of said output signal being equal to the ratio between said first reference voltage and the magnitude of said first input signal.
Claim 2
Dependent Claim
170 words
An analog to digital converter comprising: a first charge storage location; means for establishing a first charge level in said first charge storage location; means for removing a first metered plurality of charge packets from said first charge storage location, the size of the charge packets in said first plurality of charge packets being proportional to the magnitude of a first input signal; means for adding a second metered plurality of charge packets to said first charge storage location, the size of the charge packets in said second plurality proportional to the magnitude of a first reference voltage; and means for detecting the presence of said first charge level in said first charge storage location and providing an output signal in response thereto; the ratio between the number of charge packets in said first plurality to the number of charge packets in said second plurality at the time of said output signal being equal to the ratio between said first reference voltage and the magnitude of said first input signal.
Claim 3
Dependent Claim
76 words
The analog to digital converter of claim 1 wherein said first charge storage location comprises: a semiconductor substrate; first electrode means insulatingly overlying a first major surface of said substrate; second electrode means ohmically contacting said semiconductor substrate at a second major surface thereof; means for applying an electrical potential between said first and second electrodes for forming an electrical field therebetween so that a first charge storage location is formed underlying said first electrode means.
Claim 4
Dependent Claim
46 words
The analog to digital converter of claim 2 wherein said means for establishing a first charge level in said first charge storage location comprises: means for transferring charge into said first charge storage location; and means for stopping said transfer in response to said output signal.
Claim 5
Dependent Claim
55 words
The analog to digital converter of claim 3 wherein said means for transferring charge into said first charge storage location comprises: a first charge reservoir in said substrate; means for maintaining said reservoir in a substantially full condition, means for controlling the transfer of charge from said charge reservoir to said first charge storage location.
Claim 6
Dependent Claim
45 words
The analog to digital converter of claim 4 wherein said means for controlling the transfer of charge from said charge reservoir to said first charge storage location comprises: means for selectively erecting a potential barrier between said charge reservoir and said first charge storage location.
Claim 7
Dependent Claim
52 words
The analog to digital converter of claim 5 wherein said charge reservoir comprises third electrode means insulatingly overlying said substrate and means for applying an electrical potential between said second and third electrodes for forming an electrical field therebetween so that a second charge storage location is formed underlying said third electrode.
Claim 8
Dependent Claim
41 words
The analog to digital converter of claim 6 wherein said means for maintaining said reservoir in a substantially full condition comprises: a source of charge; and means for controlling the transfer of charge from said source of charge to said reservoir.
Claim 9
Dependent Claim
69 words
The analog to digital converter of claim 7 wherein said means for controlling the transfer of charge from said source of charge to said reservoir comprises: fourth electrode means overlying said semiconductor substrate; and means for applying an electrical potential between said fourth electrode means and said second electrode means for forming an electrical field therebetween so that an electrical barrier may be selectively formed underlying said fourth electrode.
Claim 10
Dependent Claim
115 words
The analog to digital converter of claim 1 wherein said means for removing a first metered plurality of charge packets from said first charge storage location comprises: a second charge storage location; means for varying the size of said second charge storage location in response to said magnitude of said first input signal; means for selectively connecting said first and second charge storage locations so that charge may be transferred from said first charge storage location to said second charge storage location in an amount proportional to the magnitude of said first input signal; means for emptying said second charge storage location after each transfer; and counting means for counting the number of transfers occurring.
Claim 11
Dependent Claim
54 words
The analog to digital converter of claim 9 wherein said second charge storage location comprises: fifth electrode means insulatingly overlying said semiconductor substrate; and means for applying an electrical potential between said fifth and second electrodes for forming an electrical field therebetween so that a charge storage location is formed underlying said fifth electrode.
Claim 12
Dependent Claim
41 words
The analog to digital converter of claim 10 wherein said means for varying the size of said second charge storage location comprises: means for varying the magnitude of said electrical potential in response to the magnitude of said first input signal.
Claim 13
Dependent Claim
17 words
The analog to digital converter of claim 10 wherein said electrical potential is said first input signal.
Claim 14
Dependent Claim
72 words
The analog to digital converter of claim 1 wherein said first charge storage location comprises: a semiconductor substrate of a first conductivity type having first and second major surfaces; a first semiconductor region of opposite conductivity type to said substrate, extending from said first surface into said substrate, towards but not meeting said second surface; first electrode means insulatingly overlying said first region; and second electrode means ohmically contacting said first region.
Claim 15
Dependent Claim
46 words
The analog to digital converter of claim 13 wherein said means for establishing a first charge level in said first charge storage location comprises: means for transferring charge into said first charge storage location; and means for stopping said transfer in response to said output signal.
Claim 16
Dependent Claim
33 words
The analog to digital converter of claim 14 wherein said means for transferring charge into said first charge storage location comprises: means for selectively applying a voltage between said first and second electrodes.
Claim 17
Dependent Claim
117 words
The analog to digital converter of claim 15 wherein said means for removing a first metered plurality of charge packets from said first charge storage location comprises: a second charge storage location; means for varying the amount of charge in said second charge storage location in response to said magnitude of said first input signal; means for selectively connecting said first and second charge storage locations so that charge may be transferred from said first charge storage location to said second charge storage location in an amount proportional to the magnitude of said first input signal; means for emptying said second charge storage location after each transfer; and counting means for counting the number of transfers occurring.
Claim 18
Dependent Claim
58 words
The analog to digital converter of claim 16 wherein said second charge storage location comprises: a second semiconductor region of opposite conductivity type to said substrate extending from said first surface into said substrate, towards but not meeting said second surface; third electrode means insulatingly overlying said second region; forth electrode means ohmically contacting said second semiconductor region.
Claim 19
Dependent Claim
45 words
The analog to digital converter of claim 17 wherein said means for varying the amount of charge in said second charge storage location comprises: means for applying adjustable electrical potential to said third and fourth electrodes, said adjustable potential being proportional to said input voltage.
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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) | 1981-01-23 | 1981-07-25 | 1982-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-23 | 1985-07-25 | 1986-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-23 | 1989-07-25 | 1990-01-24 | $7700.00 | Window Closed / Lapsed |