Patent EP0214831A2 successfully refreshed from Google Patents.
EP0214831A2
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EP
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Analog-to-digital converter and method of analog-to-digital conversion
Assignee: Fujitsu Ltd
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Filing: 1986-09-02
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Granted: —
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Expires: 2006-09-02
Abstract
Abstract The system includes: a voltage conversion circuit (11a, 11b) selectively obtaining at least three kinds of conversion voltages, i.e., a first conversion voltage which is double the input voltage (AIN), a second conversion voltage which subtracts a reference voltage (V R ) from the first conversion voltage, and a third conversion voltage which adds the reference voltage to the first conversion voltage; a comparison circuit (CPR1, CPR2) setting at least two decision level voltages (-¼VR, +¼/VR) and comparing the converted) voltage (VCMP) with each of the decision level voltages; then outputting a command signal as a result of a comparison to the voltage conversion circuit so that the voltage conversion circuit outputs one of the conversion voltages in response to the command signal; and a control circuit (SGT) for changing the connections of switches (S 1A... S 7B ) provided in the voltage conversion circuit in response to the result of the comparison by the comparison circuit.
Inventors
- 👤 Osamu Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 14:38
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/12; H03M1/34; H03M1/38; H03M1/40; H03M1/403
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
149 words
An analog-to-digital conversion system comprising: a voltage conversion means for selectively supplying one of at least three kinds of conversion voltages, i.e., a first conversion voltage which is double an input voltage, a second conversion voltage which subtracts a reference voltage from the first conversion voltage, and a third conversion voltage which adds the reference voltage to the first conversion voltage, a comparison means for receiving at least two decision level voltages, for comparing a voltage from the voltage conversion means with each of the decision level voltages, and for outputting a command signal as a result of said comparison to the voltage conversion means so as to select which kind of conversion voltage is to be supplied by the voltage conversion means, and control means for changing connection of switches provided in the voltage conversion means in response to a result of the comparison by the comparison means.
Claim 2
Dependent Claim
149 words
An analog-to-digital conversion system comprising: a voltage conversion means for selectively supplying one of at least three kinds of conversion voltages, i.e., a first conversion voltage which is double an input voltage, a second conversion voltage which subtracts a reference voltage from the first conversion voltage, and a third conversion voltage which adds the reference voltage to the first conversion voltage, a comparison means for receiving at least two decision level voltages, for comparing a voltage from the voltage conversion means with each of the decision level voltages, and for outputting a command signal as a result of said comparison to the voltage conversion means so as to select which kind of conversion voltage is to be supplied by the voltage conversion means, and control means for changing connection of switches provided in the voltage conversion means in response to a result of the comparison by the comparison means.
Claim 3
Dependent Claim
63 words
An analog-to-digital conversion system as claimed in claim 1, further comprising a calculation means constituted by at least one shift register and an adder for obtaining a digital code, the shift register being provided for converting a series code to a parallel code and performing plus/minus code conversion, and the adder being provided for adding resultant data of the plus/minus code conversion. ,,
Claim 4
Dependent Claim
32 words
An analog-to-digital conversion system as claimed in claim 1, or 2, wherein said voltage conversion means comprises at least one voltage conversion block having an operational amplifier, three capacitors and four switches.
Claim 5
Dependent Claim
46 words
An analog-to-digital conversion system as claimed in claim 1, 2, or 3 wherein said control means comprises at least one flip-flop circuit, four AND gates and two NOR gates for generating a high or low level signal in order to change connections of said switch contacts.
Claim 6
Dependent Claim
170 words
An analog-to-digital conversion method by a cyclic A/D conversion, comprising the steps of: selectively obtaining at least three kinds of conversion voltages, i.e., a first conversion voltage which is double the input voltage, a second conversion voltage which subtracts a reference voltage from the first conversion voltage, and a third conversion voltage which adds the reference voltage to the first conversion voltage in a voltage conversion means, setting at least two decision level voltages and comparing a voltage from the voltage conversion means with each of the decision level voltages, then outputting a command signal as a result of said comparison to the voltage conversion means from a comparison means, . changing connections of switch contacts provided in the voltage conversion means in response to a result of the comparison by the comparison means, outputting a conversion voltage in response to the command signal from the voltage conversion means, and obtaining digital codes by shift registers for code conversion and performing an adding operation for adding code converted digital data.
Claim 7
Dependent Claim
170 words
An analog-to-digital conversion method by a cyclic A/D conversion, comprising the steps of: selectively obtaining at least three kinds of conversion voltages, i.e., a first conversion voltage which is double the input voltage, a second conversion voltage which subtracts a reference voltage from the first conversion voltage, and a third conversion voltage which adds the reference voltage to the first conversion voltage in a voltage conversion means, setting at least two decision level voltages and comparing a voltage from the voltage conversion means with each of the decision level voltages, then outputting a command signal as a result of said comparison to the voltage conversion means from a comparison means, . changing connections of switch contacts provided in the voltage conversion means in response to a result of the comparison by the comparison means, outputting a conversion voltage in response to the command signal from the voltage conversion means, and obtaining digital codes by shift registers for code conversion and performing an adding operation for adding code converted digital data.
Claim 8
Dependent Claim
22 words
An analog-to-digital conversion method as claimed in claim 5, wherein said command signal has three kinds of values -1, 0, and +1.
Claim 9
Dependent Claim
31 words
An analog-to-digital conversion method as claimed in claim 5, or 6, wherein said decision level voltages are set one to a predetermined plus voltage and another to a symmetrically minus voltage.
Claim 10
Dependent Claim
38 words
An analog-to-digital conversion method as claimed in claim 7, wherein said predetermined plus voltage is set to a quarter of the plus reference voltage and said minus voltage is set to a quarter of the minus reference voltage.
Claim 11
Dependent Claim
91 words
An analog-to-digital conversion method as claimed in claim 7, wherein said three values (-1, 0 and +1) of the command signals as a control method are set in correspondence with the decision level voltages i.e., the command signal "-1" is set when the conversion voltage is smaller than the predetermined minus voltage, the command signal "0" is set when the conversion voltage is between the predetermined plus voltage and the predetermined minus voltage, and the command signal "1" is set when the conversion voltage is larger than the predetermined plus voltage.,
Claim 12
Dependent Claim
25 words
An analog-to-digital conversion method as claimed in any one of claims 5 to 9, wherein said decision level voltages are applied from an external circuit.
References Cited (Backward Citations)
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