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US 10,097,781 B2Granted
Analog-to-digital converter and operating method thereof
AssigneeSK hynix Inc.
InventorTae-Gyu Kim
Life of this patent
Estimating the term…
Abstract
An analog-to-digital conversion method may include: generating an initial comparison signal by comparing a pixel signal of a comparison column to a pixel signal of an adjacent column; generating a control signal for selecting a ramp signal according to the generated initial comparison signal; and performing data conversion by comparing the ramp signal selected according to the generated control signal to a difference between adjacent first and second pixel signals.
Claims16
An analog-to-digital converter comprising:
- a comparison circuit configured to compare a difference in value between adjacent first and second pixel signals with a ramp signal including a ramp-up signal and a ramp-down signal, the first pixel signal being a pixel signal of a comparison column and the second pixel signal being a pixel signal of an adjacent column to the comparison column;
- a correlated double sampling (CDS) circuit configured to perform CDS the CDS circuit being coupled between a first input terminal receiving the first pixel signal and a negative input terminal of the comparison circuit;
- a sampling circuit configured to perform sampling the sampling circuit being coupled between a second input terminal receiving the second pixel signal and a positive input terminal of the comparison circuit;
- a feedback control circuit configured to determine a ramping direction based on an initial comparison signal from the comparison circuit, and for outputting a control signal;
- a selection circuit coupled between the sampling circuit and a third input terminal receiving the ramp-up signal and a fourth input terminal receiving the ramp-down signal, and configured to select the ramp-up signal or the ramp-down signal based on the control signal;
- and
- a data conversion circuit configured to perform data conversion according to a comparison signal of the comparison circuit to a digital code data.
4 more elements
An analog-to-digital converter comprising:
- a comparison circuit configured to compare a pixel signal of a comparison column and a pixel signal of an adjacent column, and compare a ramp signal applied through a CDS circuit or a ramp signal applied through a sampling circuit to a difference value between adjacent pixels;
- the CDS circuit coupled between a first input terminal receiving the first pixel signal and a negative input terminal of the comparison circuit, and configured to perform CDS;
- the sampling circuit coupled between a second input terminal the second pixel signal and a positive input terminal of the comparison circuit, and configured to perform sampling;
- a feedback control circuit configured to determine a ramp signal switching direction based on an initial comparison signal from the comparison circuit, and outputting a control signal;
- a selection circuit coupled between a third input terminal receiving a ramp signal and the CDS circuit and the sampling circuit, and configured to select the ramp signal applied through the CDS circuit or the ramp signal applied through the sampling circuit based on the control signal from the feedback control circuit;
- and
- a data conversion circuit configured to perform data conversion according to a comparison signal of the comparison circuit to a digital code data.
4 more elements
An analog-to-digital conversion method comprising:
- generating an initial comparison signal by comparing a pixel signal of a comparison column to a pixel signal of an adjacent column;
- generating a control signal for selecting a phase of a ramp signal with respect to the pixel signal based on the initial comparison signal;
- and
- performing data conversion by comparing the selected ramp signal to a difference value between adjacent first and second pixel signals,
- wherein the generating of the control signal comprises determining a ramping direction based on the initial comparison signal and generating a control signal for selecting a ramp-up signal or ramp-down signal.
2 more elements
An analog-to-digital conversion method comprising:
- generating an initial comparison signal by comparing a pixel signal of a comparison column to a pixel signal of an adjacent column;
- generating a control signal for selecting a phase of a ramp signal with respect to the pixel signal based on the initial comparison signal;
- and
- performing data conversion by comparing the selected ramp signal to a difference value between adjacent first and second pixel signals
- wherein the generating of the control signal comprises determining a ramp signal switching direction based on the initial comparison signal and generating the control signal for selecting the ramp signal switching direction through a CDS circuit or through a sampling circuit.
2 more elements
Dependencies are inferred from the claim text.