Systems and methods to perform digital correlated double sampling using successive approximation analog to digital conversion techniques
AssigneeMicron Technology, Inc.
InventorToshinori Otaka
Life of this patent
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Abstract
An imager includes a successive approximation analog-to-digital converter (SA-ADC) and an arithmetic memory. The successive approximation analog-to-digital converter converts analog representations of pixel reset and image signals for a pixel to digital representations of the pixel reset and image signals. The arithmetic memory generates a difference signal that represents the difference between the digital representations of the pixel reset signal and the pixel image signal using a most-significant-bit-first (MSB-first) calculation.
Claims22
An imager comprising:
- a pixel array including a first pixel that provides a pixel reset signal and a pixel image signal based on photons incident on the first pixel;
- and
- a digital correlated double sampling module coupled to the pixel array, said digital correlated double sampling module comprising:
- a successive approximation analog-to-digital conversion module to convert an analog representation of the pixel reset signal for the first pixel to a digital representation of the pixel reset signal and to convert an analog representation of the pixel image signal for the first pixel to a digital representation of the pixel image signal;
- and
- an arithmetic memory module to perform a most-significant-bit-first calculation to generate a digital difference signal that represents a difference between the digital representation of the pixel reset signal and the digital representation of the pixel image signal.
A semiconductor chip comprising:
- a pixel array including a first pixel that provides a pixel reset signal and a pixel image signal based on photons incident on the first pixel;
- and
- a digital correlated double sampling module coupled to the pixel array, said digital correlated double sampling module comprising:
- a successive approximation analog-to-digital conversion module to convert an analog representation of the pixel reset signal for the first pixel to a digital representation of the pixel reset signal and to convert an analog representation of the pixel image signal for the first pixel to a digital representation of the pixel image signal, and
- an arithmetic memory module to perform a most-significant-bit-first calculation to generate a digital difference signal that represents a difference between the digital representation of the pixel reset signal and the digital representation of the pixel image signal;
- wherein the pixel array includes n columns of pixels, wherein the successive
- n
- m
- approximation analog-to-digital conversion module includes successive approximation analog-to-digital converters, wherein the arithmetic memory module includes
- n
- m
- arithmetic memories, wherein n and m are integers, and wherein n≧m.
A method of performing a digital correlated double sampling operation in an imager, comprising:
- converting an analog representation of a pixel reset signal to a digital representation of the pixel reset signal and an analog representation of a pixel image signal to a digital representation of the pixel image signal using a successive approximation analog-to-digital conversion method;
- and
- generating a digital difference signal that represents the difference between the digital representation of the pixel reset signal and the digital representation of the pixel image signal using a most-significant-bit-first method.
Dependencies are inferred from the claim text.