Analog digital converter
First Claim
1. An analog digital converter which converts an analog input signal to a digital output signal by sampling at a sampling frequency, comprising:
- N analog digital converter channels each being configured to convert the analog input signal into a plurality of channel digital signals in synchronous with sampling clocks having frequency obtained by N dividing the sampling frequency;
an adaptive filter being configured to filter at least one of the plurality of channel digital signals;
a channel synthesizer being configured to synthesize the plurality of channel digital signals respectively being output through or not through the adaptive filter from the analog digital converter channels, and outputs the digital output signal; and
a correction circuit being configured to generate a coefficient of the adaptive filter in accordance with the digital output signal and set the coefficient to the adaptive filter, whereinthe correction circuit extracts, from among an image signal component corresponding to a skew error between the N divided sampling clocks, and an analog input signal component, both of which are included in the digital output signal, a DC component of the image signal component, and generates the coefficient of the adaptive filter on the basis of the DC component of the image signal such that the DC component of the image signal component is suppressed.
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Accused Products
Abstract
An ADC which samples an analog input signal at a sampling frequency and converts the analog input signal to a digital output signal, has N analog digital converter (ADC) channels which convert the analog input signal into the digital output signal by time interleaving, a channel synthesizer which synthesizes channel digital signals output respectively by the ADC channels to generate the digital output signal, an adaptive filter provided at at least one output of the ADC channels, and a correction circuit which generates a coefficient of the adaptive filter in accordance with the digital output signal. The correction circuit calculates a DC component of an image signal component, from among an analog input signal component and the image signal component corresponding to error, both being included in the digital output signal, and calculates the coefficient such that the DC component is suppressed on the basis of the DC component.
18 Citations
17 Claims
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1. An analog digital converter which converts an analog input signal to a digital output signal by sampling at a sampling frequency, comprising:
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N analog digital converter channels each being configured to convert the analog input signal into a plurality of channel digital signals in synchronous with sampling clocks having frequency obtained by N dividing the sampling frequency; an adaptive filter being configured to filter at least one of the plurality of channel digital signals; a channel synthesizer being configured to synthesize the plurality of channel digital signals respectively being output through or not through the adaptive filter from the analog digital converter channels, and outputs the digital output signal; and a correction circuit being configured to generate a coefficient of the adaptive filter in accordance with the digital output signal and set the coefficient to the adaptive filter, wherein the correction circuit extracts, from among an image signal component corresponding to a skew error between the N divided sampling clocks, and an analog input signal component, both of which are included in the digital output signal, a DC component of the image signal component, and generates the coefficient of the adaptive filter on the basis of the DC component of the image signal such that the DC component of the image signal component is suppressed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 15)
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10. An correction circuit for an analog digital converter which converts the analog input signal to a digital output signal by sampling at a sampling frequency, the analog digital converter having,
N analog digital converter channels each being configured to convert the analog input signal to a plurality of channel digital output signals in synchronous with sampling clocks having frequency obtained by N dividing the sampling frequency; -
an adaptive filter being configured to filter at least one of the plurality of channel digital signals; and a channel synthesizer being configured to synthesize the plurality of channel digital signals respectively being output through or not through the adaptive filter from the analog digital converter channels, and outputs the digital output signal, wherein the correction circuit comprising; a first calculator being configured to extract, from among an image signal component corresponding to a skew error between the N divided sampling clocks, and an analog input signal component, both of which are included in the digital output signal, a DC component of the image signal component; and
from the digital output signal; anda second calculator being configured to generate the coefficient of the adaptive filter on the basis of the DC component of the image signal such that the DC component of the image signal component is suppressed, and set the coefficient to the adaptive filter. - View Dependent Claims (11, 12, 16)
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13. An correction method for an analog digital converter which converts the analog input signal to a digital output signal by sampling at a sampling frequency, the analog digital converter having:
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N analog digital converter channels each being configured to convert the analog input signal to a plurality of channel digital signals in synchronous with sampling clocks having frequency obtained by N dividing the sampling frequency; an adaptive filter being configured to filter at least one of the plurality of channel digital signals; and a channel synthesizer being configured to synthesize the plurality of channel digital signals respectively being output through or not through the adaptive filter from the analog digital converter channels, and outputs the digital output signal, the method comprising; extracting, from among an image signal component corresponding to a skew error between the N divided sampling clocks, and an analog input signal component, both of which are included in the digital output signal, a DC component of the image signal component; generating the coefficient of the adaptive filter on the basis of the DC component of the image signal such that the DC component of the image signal component is suppressed; and setting the coefficient in the adaptive filter. - View Dependent Claims (14, 17)
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Specification