US4734678A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High-resolution A/D converter
Assignee: Seiko Instruments Inc
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Filing: 1987-03-05
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Granted: 1988-03-29
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Expires: 2007-03-05
Abstract
Abstract In order to provide a high-resolution A/D converter, the present invention is based upon the combination of two D/A converters, an input switch, an adder, an amplifier and a processor, wherein characteristics of the two D/A converters are learned relying upon the work of the processor and the switch, and the final digital output is corrected relying upon the thus learned characteristics to accomplish a high resolution.
Inventors
- 👤 Masafumi Take
- 👤 Haruo Takeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:49
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/06; H03M1/0617; H03M1/0675; H03M1/12; H03M1/34; H03M1/38; H03M1/46; H03M1/66; H03M1/74
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
150 words
A high-resolution A/D converter which comprises: a first D/A converter; a switch for selecting an output signal of said first D/A converter and an analog input signal; a second D/A converter; an adder which performs the addition or subtraction of a signal that has passed through said switch and an output signal of said second D/A converter; an amplifier for amplifying the output signal of said adder; an A/D converter for converting the output signal of said amplifier into a digital value; and a processor which reads the output of said A/D converter and give input values to said first and second D/A converters; wherein said processor stores all minimum bit widths of said first and second D/A converters, when said first D/A converter is selected as an input by said switch, and corrects the digital output value when the analog signal is selected as an input by said switch.
Claim 2
Dependent Claim
150 words
A high-resolution A/D converter which comprises: a first D/A converter; a switch for selecting an output signal of said first D/A converter and an analog input signal; a second D/A converter; an adder which performs the addition or subtraction of a signal that has passed through said switch and an output signal of said second D/A converter; an amplifier for amplifying the output signal of said adder; an A/D converter for converting the output signal of said amplifier into a digital value; and a processor which reads the output of said A/D converter and give input values to said first and second D/A converters; wherein said processor stores all minimum bit widths of said first and second D/A converters, when said first D/A converter is selected as an input by said switch, and corrects the digital output value when the analog signal is selected as an input by said switch.
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) | 1991-03-29 | 1991-09-28 | 1992-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-29 | 1995-09-28 | 1996-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-29 | 1999-09-28 | 2000-03-29 | $7700.00 | Window Closed / Lapsed |