CMOS image sensor capable of performing analog correlated double sampling
AssigneeMagnaChip Semiconductor, Ltd.
InventorHaek-Soo Oh
Life of this patent
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Abstract
A complementary metal oxide semiconductor (CMOS) image sensor capable of performing an analog correlated double sampling method is provided. The CMOS image sensor includes an image capturing unit for capturing an analog signal corresponding to an image of a subject; an analog-digital converting unit for converting the analog signal into a digital signal by using a ramp signal decreasing in a fixed slope according to a reference clock; a ramp signal generation unit for providing the ramp signal to the analog-digital converter; and a control unit for providing said units with control signals and outputting data to the outside through an interface.
Claims6
A complementary metal oxide semiconductor (CMOS) image sensor, comprising:
- an image capturing unit for capturing an analog signal corresponding to an image of a subject;
- an analog-digital converting unit for converting the analog signal into a digital signal by using a ramp signal decreasing in a fixed slope according to a reference clock;
- a ramp signal generation unit for providing the ramp signal to the analog-digital converter;
- and
- a control unit for providing said units with control signals and outputting data to the outside through an interface,
- wherein the analog-digital converter includes:
- a chopper comparator comparing the analog signal and the ramp signal;
- an input capacitor inducing a voltage value corresponding to a start voltage of the ramp signal in a reset mode and a voltage value corresponding to the ramp signal decreasing according to the reference clock in a counter mode;
- and
- a counter,
- wherein the chopper comparator has:
- a plurality of inverters having a common source amplifier structure;
- a plurality of switches controlled by the control unit;
- and
- a plurality of capacitors.
Dependencies are inferred from the claim text.