Analog-to-digital converter, photoelectric conversion device, and imaging system

摘要

A photoelectric conversion device includes a counter circuit configured to count a first clock signal to output a count signal thereof, a second clock signal generation unit configured to generate a second clock signal based on the first clock signal, and a clock synchronization unit configured to output a count start signal in synchronization with the second clock signal, wherein the counter circuit performs a counting operation in response to the count start signal synchronized with the second clock signal.

主权项

1. A photoelectric conversion device comprising a pixel array including a plurality of columns of pixels, a signal processing unit, and a plurality of analog-to-digital converters, each including a comparator for comparing a reference signal with an analog signal and a storage unit, the photoelectric conversion device further comprising:
a reference signal supply unit configured to supply the reference signal, which varies with time, to each comparator of the plurality of analog-to-digital converters; a second clock signal generation unit configured to generate a second clock signal based on a first clock signal, and to output the second clock signal; a clock synchronization unit configured to output a count start signal in synchronization with the second clock signal output from the second clock signal generation unit; and a counter circuit configured to perform a counting operation of generating a count signal by counting the first clock signal in response to the count start signal output from the clock synchronization unit, and to output the count signal to each storage unit of the plurality of analog-to-digital converters, wherein each storage unit of the plurality of analog-to-digital converters is configured to store the count signal according to an output of the corresponding comparator, wherein each storage units of the plurality of analog-to-digital converters includes a first storage unit and a second storage unit, and wherein the signal processing unit performs a differential processing of the count signals output from the first storage unit and the second storage unit.