Stepped ramp signal generator and image sensor using the same
AssigneeDongbu HiTek Co., Ltd.
InventorsJeongkwon NAM, Haksoo Oh
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Abstract
A stepped ramp signal generator includes a ramp signal generation unit configured to provide final values of previous stepped ramp signals as initial values of the next stepped ramp signals. The ramp signal generation unit includes a plurality of matching resistors, and a plurality of holders installed between the matching resistors, each holder storing a final value across a previous matching resistor and providing the final value to a next matching resistor.
Claims13
An apparatus comprising a stepped ramp signal generator, wherein the stepped ramp signal generator comprises:
- a ramp signal generation unit, wherein:
- the ramp signal generation unit is configured to provide final values of a first stepped ramp signals as initial values of a second stepped ramp signals, wherein the second stepped ramp signals are subsequent to the first stepped ramp signals.
An apparatus comprising an image sensor, wherein the image sensor comprises:
- an active pixel sensor array configured to sense light to generate an image signal;
- a ramp signal generator configured to generate K first stepped ramp signals and K second stepped ramp signals to provide a final value of a (j−1)-th first stepped ramp signal as an initial value of a j-th stepped ramp signal, wherein j is a natural number being larger than 1;
- and
- an analog-to-digital converter configured to perform a correlated-double-sampling on the image signal to convert the image signal into a digital signal using the K first stepped ramp signals and the K second stepped ramp signals.
Dependencies are inferred from the claim text.