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US 4,751,496 AGranted
Wide dynamic range analog to digital conversion method and system
AssigneeTEAC Corporation
InventorsTetsuro Araki, Mitsumasa Kubo
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AssigneeTEAC Corporation
InventorsTetsuro Araki, Mitsumasa Kubo
Estimating the term…
A method and apparatus well suited for digitizing an audio signal with as wide a dynamic range as possible. An analog dither signal is added to an analog audio or like data signal to provide an analog data/dither signal. This analog data/dither signal and the analog dither signal are both converted into a digital data/dither signal and a digital dither signal respectively, and the digital dither signal is subsequently subtracted from the digital data/dither signal to obtain a digital data signal equivalent to the analog data signal. The magnitude of the incoming analog data signal may be so high that when the analog dither signal is added thereto, the magnitude of the resulting data/dither signal may exceed the capacity of the analog to digital converter in use. In that case the analog dither signal is either gated off or reduced in magnitude, with the result that the analog to digital converter inputs either the data signal only or the data/dither signal having a magnitude not exceeding its capacity.
In a method of digitizing an analog data signal by generating an analog dither signal of smaller magnitude than the analog data signal, adding the analog dither signal to the analog data signal to provide an analog data/dither signal, converting the analog data/dither signal and the analog dither signal into a digital data/dither signal and a digital dither signal respectively, and subtracting the digital dither signal from the digital data/dither signal to obtain a digital data signal equivalent to the analog data signal, the improvement which comprises ascertaining whether or not the magnitude of the analog data/dither signal will exceed the capacity of an analog to digital converter used for the conversion of at least the data/dither signal, and inhibiting the addition of the analog dither signal to the analog data signal when the magnitude of the analog data/dither signal is ascertained to exceed the capacity of the analog to digital converter.
In a method of digitizing an analog data signal by adding an analog dither signal to the analog data signal to provide an analog data/dither signal, converting the analog data/dither signal and the analog dither signal into a digital data/dither signal and a digital dither signal respectively, and subtracting the digital dither signal from the digital data/dither signal to obtain a digital data signal equivalent to the analog data signal, the improvement which comprises comparing the magnitude of the analog data/dither signal with a reference magnitude predetermined in relation to the capacity of an analog to digital converter used for the conversion of at least the data/dither signal, and inhibiting the addition of the analog dither signal to the analog data signal when the magnitude of the analog data/dither signal exceeds the reference magnitude.
In a method of digitizing an analog data signal by generating an analog dither signal of smaller magnitude than the analog data signal, adding the analog dither signal to the analog data signal to provide an analog data/dither signal, converting the analog data/dither signal and the analog dither signal into a digital data/dither signal and a digital dither signal respectively, and subtracting the digital dither signal from the digital data/dither signal to obtain a digital data signal equivalent to the analog data signal, the improvement which comprises ascertaining whether or not the magnitude of the analog data/dither signal will exceed the capacity of an analog to digital converter used for the conversion of at least the data/dither signal, and, when the magnitude of the analog data/dither signal is ascertained to exceed the capacity of the analog to digital converter, reducing the magnitude of the analog dither signal to an extent necessary to hold the magnitude of the analog data/dither signal within the capacity of the analog to digital converter, wherein whether or not the magnitude of the analog data/dither signal will exceed the capacity of the analog to digital converter is ascertained by comparing the magnitude of the incoming analog data signal with a reference magnitude predetermined in relation to the capacity of the analog to digital converter.
In a method of digitizing an analog data signal by adding an analog dither signal to the analog data signal to provide an analog data/dither signal, converting the analog data/dither signal and the analog dither signal into a digital data/dither signal and a digital dither signal respectively, and subtracting the digital dither signal from the digital data/dither signal to obtain a digital data signal equivalent to the analog data signal, the improvement which comprises comparing the magnitude of the analog data/dither signal with a reference magnitude predetermined in relation to the capacity of an analog to digital converter used for the conversion of at least the data/dither signal, and, when the magnitude of the analog data/dither signal exceeds the reference magnitude, reducing the magnitude of the analog dither signal to an extent necessary to hold the magnitude of the analog data/dither signal within the capacity of the analog to digital converter.
A system for digitizing an analog data signal, comprising:
A system for digitizing an analog data signal, comprising:
A system for digitizing an analog data signal, comprising:
A system for digitizing an analog data signal, comprising:
A system for digitizing an analog data signal, comprising:
A system for digitizing an analog data signal, comprising:
A system for digitizing an analog data signal, comprising:
Dependencies are inferred from the claim text.