Patent US3597761A successfully refreshed from Google Patents.
US3597761A
Expired / Lapsed
US
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High-speed analog-to-digital converter and method therefor
Assignee: American Astrionics Inc
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Filing: 1969-11-14
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Granted: 1971-08-03
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Expires: 1989-11-14
Abstract
Abstract An analog-to-digital converter having first and second comparator banks where the analog input voltage is applied to both of the comparator banks simultaneously to allow the second subranging comparator bank to slew and settle simultaneously with the switching operations of the first comparator bank. Discrete reference level voltages are selected by the first comparator bank in response to the analog input voltage and switched to the second comparator bank and serve to adjust the threshold detection level of the second bank. In an alternative embodiment two sample and hold circuits alternately apply samples taken at different times to the two comparator banks.
Inventors
- 👤 Jerry J Fraschilla
- 👤 Robert D Caveney
- 👤 Ronnie M Harrison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:21
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/12; H03M1/14; H03M1/145; H03M1/146
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
145 words
A method of converting an input electric signal from an analog to a digital format having a plurality of information bits where first comparator means provide the most significant bits of said digital format and second comparator means provide the least significant bits, said method comprising the following steps: coupling said input signal to said first comparator means; comparing said input signal with a plurality of discrete reference voltage levels and selecting one of said reference voltages approximately equal to the magnitude of said input signal to provide said most significant bits; thereafter coupling said one reference voltage to said second comparator means to adjust the reference threshold thereof; coupling said input signal to said second comparator means; and subtracting said one reference voltage from said input signal and comparing the difference amount to a plurality of reference levels to provide said least significant bits.
Claim 2
Independent Claim
145 words
A method of converting an input electric signal from an analog to a digital format having a plurality of information bits where first comparator means provide the most significant bits of said digital format and second comparator means provide the least significant bits, said method comprising the following steps: coupling said input signal to said first comparator means; comparing said input signal with a plurality of discrete reference voltage levels and selecting one of said reference voltages approximately equal to the magnitude of said input signal to provide said most significant bits; thereafter coupling said one reference voltage to said second comparator means to adjust the reference threshold thereof; coupling said input signal to said second comparator means; and subtracting said one reference voltage from said input signal and comparing the difference amount to a plurality of reference levels to provide said least significant bits.
Claim 3
Dependent Claim
23 words
A method as in claim 1 where said steps of coupling said input to said first and second comparator means are performed simultaneously.
Claim 4
Dependent Claim
31 words
A method as in claim 1 including the step of precharging said second comparator means with said input signal prior to application of a reference voltage to said second comparator means.
Claim 5
Dependent Claim
51 words
A method as in claim 1 where said subtracting step includes the step of translating said input signal successively downward by steps and comparing said one reference voltage with said input signal reduced by a number of steps to provide a comparison said number of steps providing said least significant bits.
Claim 6
Independent Claim
237 words
A method of converting an input electric signal from an analog to a digital format having a plurality of information bits where first comparator means provide the most significant bits of said digital format and second comparator means provide the least significant bits, said method comprising the following steps: sampling an input waveform at a first instant in time to provide a first input electric signal coupling said first input signal to said first compaRator means; comparing said first input signal with a plurality of discrete reference voltage levels and selecting one of said reference voltages approximately equal to the magnitude of said input signal to provide said most significant bits; sampling said input waveform at a second later instant in time to provide a second electric input signal; coupling said second input signal to said first comparator means comparing said second input signal with said plurality of discrete reference voltage levels and selecting one of said reference voltages approximately equal to the magnitude of said input signal to provide said most significant bits; thereafter respectively coupling said selected reference voltages to said second comparator means to adjust the reference threshold thereof; coupling said first and second input signals to said second comparator means; and respectively subtracting said selected reference voltages from said respective input signals and comparing the difference amounts to a plurality of reference levels to provide said least significant bits for each input signal.
Claim 7
Independent Claim
237 words
A method of converting an input electric signal from an analog to a digital format having a plurality of information bits where first comparator means provide the most significant bits of said digital format and second comparator means provide the least significant bits, said method comprising the following steps: sampling an input waveform at a first instant in time to provide a first input electric signal coupling said first input signal to said first compaRator means; comparing said first input signal with a plurality of discrete reference voltage levels and selecting one of said reference voltages approximately equal to the magnitude of said input signal to provide said most significant bits; sampling said input waveform at a second later instant in time to provide a second electric input signal; coupling said second input signal to said first comparator means comparing said second input signal with said plurality of discrete reference voltage levels and selecting one of said reference voltages approximately equal to the magnitude of said input signal to provide said most significant bits; thereafter respectively coupling said selected reference voltages to said second comparator means to adjust the reference threshold thereof; coupling said first and second input signals to said second comparator means; and respectively subtracting said selected reference voltages from said respective input signals and comparing the difference amounts to a plurality of reference levels to provide said least significant bits for each input signal.
Claim 8
Dependent Claim
36 words
A method as in claim 5 where said step of providing said least significant bits for said first input signal is concurrent with said step of coupling said second input signal to said first comparator means.
Claim 9
Dependent Claim
157 words
Apparatus for converting an input electric signal from an analog to a digital format having a plurality of information bits comprising: a voltage source for providing a plurality of discrete reference voltage levels; first comparator means for comparing said input signal with said discrete voltage levels and for selecting one of said reference voltages approximately equal to the magnitude of said input signal to provide the most significant bits of said digital format; second comparator means; means for coupling said input signal to said second comparator means for precharging said second comparator means; means for coupling said one reference voltage to said second comparator means, said second comparator means including means for subtracting said one reference voltage from said input signal and for comparing the difference amount with a plurality of second reference levels to select one of said reference levels approximately equal to said difference amount to provide the least significant bits of the digital format.
Claim 10
Dependent Claim
157 words
Apparatus for converting an input electric signal from an analog to a digital format having a plurality of information bits comprising: a voltage source for providing a plurality of discrete reference voltage levels; first comparator means for comparing said input signal with said discrete voltage levels and for selecting one of said reference voltages approximately equal to the magnitude of said input signal to provide the most significant bits of said digital format; second comparator means; means for coupling said input signal to said second comparator means for precharging said second comparator means; means for coupling said one reference voltage to said second comparator means, said second comparator means including means for subtracting said one reference voltage from said input signal and for comparing the difference amount with a plurality of second reference levels to select one of said reference levels approximately equal to said difference amount to provide the least significant bits of the digital format.
Claim 11
Dependent Claim
37 words
Apparatus as in claim 7 where said coupling means for precharging said second comparator means couples said input signal to an input terminal of said second comparator means to which said one reference voltage is also coupled.
Claim 12
Dependent Claim
29 words
Apparatus as in claim 7 together with means for sequentially initiating said precharging of said second comparator means before said one reference is coupled to said second comparator means.
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) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |