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US4887085A
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Time continuous, differential analog-to-digital converter
Assignee: Microsemi Semiconductor US Inc
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Filing: 1988-12-19
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Granted: 1989-12-12
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Expires: 2008-12-19
Abstract
Abstract The invention is for an analog-to-digital converter which is useful for audio applications owing to its insensitivity to noise. The converter achieves this insensitivity by utilizing a differential, common node integrator having a non-switching capacitive feed-back loop.
Inventors
- 👤 Miki Z. Moyal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:24
CPC Classifications
H; H03; H03M; H03M3/00; H03M3/30; H03M3/39
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
117 words
A time continuous, over-sampled, differential analog-to-digital converter, comprising: input means defining a split input stage for supplying analog current signals; a continuous, differential, non-switch capacitive integrator having common node feed-back, operatively connected to said split input stage; a differential current generator forming a feedback loop circuit with said continuous, differential, non-switch capacitive, common node integrator for providing generated current signals; a comparator operatively connected to said differential integrator within said loop circuit for digitizing analog signals, and for comparing generated current signals with analog current signals; and a clocked, binary counter operatively connected to said comparator for incrementing or decrementing one step in response to each comparison of a generated current signal with an analog current signal.
Claim 2
Dependent Claim
117 words
A time continuous, over-sampled, differential analog-to-digital converter, comprising: input means defining a split input stage for supplying analog current signals; a continuous, differential, non-switch capacitive integrator having common node feed-back, operatively connected to said split input stage; a differential current generator forming a feedback loop circuit with said continuous, differential, non-switch capacitive, common node integrator for providing generated current signals; a comparator operatively connected to said differential integrator within said loop circuit for digitizing analog signals, and for comparing generated current signals with analog current signals; and a clocked, binary counter operatively connected to said comparator for incrementing or decrementing one step in response to each comparison of a generated current signal with an analog current signal.
Claim 3
Dependent Claim
47 words
The time continuous, over-sampled, differential analog-to-digital converter of claim 1, wherein said input means comprises a pair of operational amplifiers fed by a split analog voltage source and a pair of resistors respectively connected to said operational amplifiers for providing differential analog current signals from analog voltages.
Claim 4
Dependent Claim
19 words
The time continuous, over-sampled, differential analog-to-digital converter of claim 1, wherein said binary counter is clocked at 2.048 MHz.
Claim 5
Dependent Claim
22 words
The time continuous, over-sampled, differential analog-to-digital converter of claim 1, wherein said differential current generator comprises a 6.02 dB per bit DAC.
Claim 6
Dependent Claim
42 words
The time continuous, over-sampled, differential analog-to-digital converter of claim 1, wherein said continuous, differential, non-switch capacitive common node integrator is operatively connected within said loop with said differential current generator, wherein said loop comprises a pair of split capacitor and resistor elements.
Claim 7
Dependent Claim
18 words
The time continuous, over-sampled, differential analog-to-digital converter of claim 1, wherein said converter forms a CMOS integrated circuit.
Claim 8
Dependent Claim
19 words
The time continuous, over-sampled, differential analog-to-digital converter of claim 1, wherein said converter forms part of an audio system.
Claim 9
Dependent Claim
18 words
The time continuous, over-sampled, differential analog-to-digital converter of claim 1, wherein said converter forms part of a CODEC.
Claim 10
Dependent Claim
18 words
The time continuous, over-sampled, differential analog-to-digital converter of claim 1, wherein said converter forms part of a MODEM.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-11 | 1993-06-12 | 1993-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-11 | 1997-06-12 | 1997-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-11 | 2001-06-12 | 2001-12-12 | $7700.00 | Window Closed / Lapsed |