US3585631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Square law analog-to-digital converter
Assignee: Westinghouse Electric Corp
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Filing: 1969-11-26
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Granted: 1971-06-15
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Expires: 1989-11-26
Abstract
Abstract A plural stage analog-to-digital converter with a square law transfer characteristic is described. The converter comprises in a typical embodiment three identical stages with the first stage having a fixed reference voltage applied thereto. More or less stages can be used as desired. A pair of identical resistive ladder networks having the resistors thereof arranged in quadratic fashion is employed in each of the stages of the converter. The ladder networks of the first stage divide the fixed reference voltage applied to the first stage into a plurality of voltages each of predetermined magnitude. A plurality of comparators is employed in each stage to compare a divided reference voltage applied to the respective stages with an unknown analog input signal which is also applied to each stage. The reference voltages for the second stage are obtained from the first stage and the reference voltages for the third stage are obtained from the second stage. A decoder is coupled to each stage of the converter for deriving an output representative of the square of the level of the analog signal applied to the converter.
Inventors
- 👤 Ranier F Mccown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:35
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/06; H03M1/08
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
274 words
A plural stage analog-to-digital converter wherein each of the stages of said converter are connected in parallel with each other and the first stage of said converter has a fixed reference voltage source applied thereto, circuit means for applying an input analog signal to each of said stages, at least the first and second stages of said converter each having a first resistive ladder network connected in parallel with a second identical resistive ladder network, said first and second resistive ladder networks of said first stage being connected across said reference voltage source for dividing said reference voltage source into a plurality of voltages each of predetermined magnitude, said first stage of said converter having a plurality of comparator devices operatively connected to the first resistive ladder network thereof and also operatively connected to said input analog signal circuit means, said comparators of said first stage being arranged to compare said input analog signal with said plurality of voltages, first means operatively connected to the outputs of said comparators of said first stage and adapted to select the voltage levels of said plurality of voltages between which said input analog signal falls, second means operatively connected to said first means and said second resistive ladder network of said first stage for interconnecting that portion of the second resistive ladder network of said first stage across the first ladder network of said second stage whereby said selected levels of said plurality of voltages between which said input signal falls is supplied to said second stage, and means coupled to each stage of said converter to derive a digital output representative of said analog input signal.
Claim 2
Dependent Claim
274 words
A plural stage analog-to-digital converter wherein each of the stages of said converter are connected in parallel with each other and the first stage of said converter has a fixed reference voltage source applied thereto, circuit means for applying an input analog signal to each of said stages, at least the first and second stages of said converter each having a first resistive ladder network connected in parallel with a second identical resistive ladder network, said first and second resistive ladder networks of said first stage being connected across said reference voltage source for dividing said reference voltage source into a plurality of voltages each of predetermined magnitude, said first stage of said converter having a plurality of comparator devices operatively connected to the first resistive ladder network thereof and also operatively connected to said input analog signal circuit means, said comparators of said first stage being arranged to compare said input analog signal with said plurality of voltages, first means operatively connected to the outputs of said comparators of said first stage and adapted to select the voltage levels of said plurality of voltages between which said input analog signal falls, second means operatively connected to said first means and said second resistive ladder network of said first stage for interconnecting that portion of the second resistive ladder network of said first stage across the first ladder network of said second stage whereby said selected levels of said plurality of voltages between which said input signal falls is supplied to said second stage, and means coupled to each stage of said converter to derive a digital output representative of said analog input signal.
Claim 3
Dependent Claim
57 words
A plural stage analog-to-digital converter as defined in claim 1 wherein the resistors employed in said first and second resistive ladder networks of said stages of said converter are arranged in quadratic fashion such that said means coupled to each stage of said converter derives a digital output representative of the square of said analog input signal.
Claim 4
Dependent Claim
82 words
A plural stage analog-to-digital converter as defined in claim 1 wherein each of said comparators of said first stage has a pair of input terminals and a pair of output terminals with one input terminal of each comparator being operatively connected to said first ladder network of said first stage such that a voltage of predetermined magnitude is applied to each of said comparators, the other input terminal of each of said comparators being adapted for connection to said input analog signal.
Claim 5
Dependent Claim
89 words
A plural stage analog-to-digital converter as defined in claim 3 wherein said first means of said first stage comprises a plurality of AND gate devices, each of said AND gate devices having a pair of input terminals and an output terminal with the input of each AND gate device being operatively connected to an adjacent pair of comparators such that each one of the pair of output terminals of each of said comparators is connected to one of the input terminals of an adjacent pair of AND gate devices.
Claim 6
Dependent Claim
137 words
A plural stage analog-to-digital converter as defined in claim 4 wherein said second means of said first stage comprises a plurality of gate devices, each of said gate devices having a pair of input terminals and an output terminal with one input terminal of each adjacent gate device being operatively connected to said second resistive ladder network of said first stage and the other input terminal of each adjacent pair of said gate devices being connected to the output terminal of one of said AND gate devices such that an output signal appearing on the output of any of said AND gate devices is operative to enable an adjacent pair of said gate devices and interconnect that portion of the second resistive ladder network of said first stage across the first ladder network of said second stage.
Claim 7
Dependent Claim
57 words
A plural stage analog-to-digital converter as defined in claim 5 wherein the resistors employed in said first and second resistive ladder networks of said stages of said converter are arranged in quadratic fashion such that said means coupled to each stage of said converter derives a digital output representative of the square of said analog input signal.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-14 | 1974-12-14 | 1975-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-14 | 1978-12-14 | 1979-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-14 | 1982-12-14 | 1983-06-15 | $7700.00 | Window Closed / Lapsed |