Analog-to-digital converter with digital-to-analog converter and comparator
AssigneesMitsubishi Electric Semiconductor Software Co., Ltd., Mitsubishi Denki Kabushiki Kaisha
InventorNobuya Uda
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Abstract
An analog-to-digital converter includes a comparator for comparing a voltage output by a digital-to-analog converter with an input analog voltage at each bit of an n-bit word. The input analog voltage and the analog output voltage of the digital-to-analog converter are alternatingly used as the reference in the comparison, i.e., for every other bit of the n bits. A one-bit result-of-comparison signal indicative of the result of the comparison is output for each of the n bits. Only alternating result-of-comparison signals are inverted and the inverted and non-inverted result-of-comparison signals are stored in a successive approximation register as the converted digital signal and are supplied to the digital-to-analog converter for use in the comparison.
Claims9
An analog-to-digital converter for converting an input analog voltage into an n-bit digital signal, where n is a natural number, the analog-to-digital converter comprising:
- a digital-to-analog converter for converting an n-bit digital signal into an analog reference voltage;
- comparing means for comparison of the analog reference voltage and an input analog voltage at each of n bits of the n-bit digital signal, the analog reference voltage and the input analog voltage being used in alternation, for every other bit of the n-bits, as a reference in the comparison, and for outputting for each comparison a one-bit result-of-comparison signal indicative of a result of the comparison;
- signal inverting means for inverting only alternating result-of-comparison signals and for outputting inverted and non-inverted result-of-comparison signals;
- and
- a successive approximation register having storage areas respectively corresponding to the n bits, for successively storing the inverted and non-inverted result-of-comparison signals for each of the n bits as the n-bit digital signal, for outputting the n-bit digital signal as a digital signal, and for transferring the n-bit digital signal to said digital-to-analog converter.
Dependencies are inferred from the claim text.