Digital equalization of time interleaved analog to digital converters
First Claim
1. In an analog-to-digital converter circuit having a plurality of time interleaved analog-to-digital converters for receiving an analog input signal and generating a plurality of digital signals, the improvement comprisingequalization means for compensating for individual variations in converter characteristics found amongst the plurality of analog-to-digital converters, said equalization means including:
- a reference converter being chosen from one of said analog-to-digital converters, each of the remaining plurality of analog-to-digital converters being referenced to said reference converter;
means for providing a differential response between said reference converter and each of the remaining converters; and
equalization filter means having individual equalization filters coupled to each of said remaining analog-to-digital converters, each filter receiving input signals from each of the plurality of analog-to-digital converters and having filter coefficients which provide compensation for variations in timing and frequency/phase response between said reference converter and each of the remaining converters.
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Accused Products
Abstract
An equalization method is provided for compensating for variations in the characteristics of individual analog-to-digital converters found in a time interleaved analog-to-digital converter circuit. One of a plurality of converters is chosen as a reference converter. Individual characteristics of the remaining converters are compared with the reference converter to provide differential responses therewith. The differential responses are equalized to provide compensation for variations in gain, offset, phase/frequency response, and timing found amongst the plurality of time interleaved converters.
109 Citations
17 Claims
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1. In an analog-to-digital converter circuit having a plurality of time interleaved analog-to-digital converters for receiving an analog input signal and generating a plurality of digital signals, the improvement comprising
equalization means for compensating for individual variations in converter characteristics found amongst the plurality of analog-to-digital converters, said equalization means including: -
a reference converter being chosen from one of said analog-to-digital converters, each of the remaining plurality of analog-to-digital converters being referenced to said reference converter; means for providing a differential response between said reference converter and each of the remaining converters; and equalization filter means having individual equalization filters coupled to each of said remaining analog-to-digital converters, each filter receiving input signals from each of the plurality of analog-to-digital converters and having filter coefficients which provide compensation for variations in timing and frequency/phase response between said reference converter and each of the remaining converters. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. In an analog-to-digital converter circuit having a plurality of time interleaved analog-to-digital converters for receiving an analog input signal and generating a plurality of digital signals, the improvement comprising:
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equalization means for compensating for individual variations in converter characteristics found amongst the plurality of analog-to-digital converters, said equalization means including; a reference converter being chosen from one of said analog-to-digital converters, each of the remaining plurality of analog-to-digital converters being referenced to said reference converter; means for providing a differential response between said reference converter and each of the remaining converters; equalization filter means having individual equalization filters coupled to each of said remaining analog to-digital converters, said filter means receiving input signals from each of the plurality of analog-to-digital converters and having filter coefficients which provide compensation for variations in timing and frequency/phase response between said reference converter and each of the remaining converters; gain equalization means for compensating for variations in gain between said reference converter and each of the remaining converters; and offset equalization means for adjusting for variations in converter offsets found between said reference converter and each of the remaining converters. - View Dependent Claims (10, 11, 12)
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13. In an analog-to-digital converter circuit having a plurality of time interleaved analog-to-digital converters for receiving an analog input signal and generating a plurality of digital signals, a method for removing converter offsets and relative variations of gain, timing, and frequency/phase response found amongst the plurality of analog-to-digital converters to compensate for differences amongst the plurality of converters, said method comprising;
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choosing one of said plurality of analog-to-digital converters as a reference; comparing each of the remaining plurality of analog-to-digital converters with said reference converter; subtracting the frequency response and gain of the reference converter from each of the remaining plurality of analog-to-digital converters to obtain differential response of gain, timing, and phase/frequency response; and equalizing said differential responses to thereby compensate for variations amongst the plurality of converters. - View Dependent Claims (14, 15)
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16. An analog-to-digital converter circuit for receiving an analog input signal and generating a plurality of digital signals, said circuit comprising:
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a plurality of time interleaved analog-to-digital converters; one of said analog-to-digital converters being chosen as a reference converter; each of the remaining plurality of analog-to-digital converters being referenced to said reference converter; and equalization means for providing compensation for individual variations of gain, timing, frequency/phase response and converter offsets found amongst the plurality of analog-to-digital converters, said equalization means including equalization filter means coupled to each of said remaining analog-to-digital converters, said filter means receiving input signals from each of the plurality of analog-to-digital converters and having filter coefficients which provides for compensation for said individual converter variations of timing and frequency/phase response. - View Dependent Claims (17)
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Specification