Method of operating ripple counter, image sensor having ripple counter, method of operating image sensor, and analog-to-digital converter of image sensor

An image sensor comprising:

• a controller configured to generate a first control signal and a second control signal;
• and
• a plurality of up/down ripple counters configured to receive a plurality of operation control signals, the plurality of operation control signals being based at least in part on the first control signal,
• each of the plurality of up/down ripple counters configured to perform one of a stop operation and a count operation in response to a corresponding one of the operation control signals and perform the count operation as one of an up-count operation and a down-count operation based on the second control signal, wherein each of the up/down ripple counters includes,
• N number of latches, wherein N>2 and N is a natural number, and
• a switch block configured to feed back one of an output signal and a complementary output signal of each of the N number of latches as an input signal to each of the N number of latches in response to a corresponding one of the operation control signals, and connect one of an output terminal and a complementary output terminal of each of the N number of latches to a clock terminal of a next latch of each of the N number of latches in response to the second control signal.

An image sensor comprising:

• a controller configured to generate a first control signal and a second control signal;
• and
• a plurality of up/down ripple counters configured to receive a plurality of operation control signals, the plurality of operation control signals being based at least in part on the first control signal,
• each of the plurality of up/down ripple counters configured to perform one of a stop operation and a count operation in response to a corresponding one of the operation control signals and perform the count operation as one of an up-count operation and a down-count operation based on the second control signal, wherein each of the up/down ripple counters includes,
• a plurality of latches, and
• a switch block configured to receive the second control signal and connect one of each of output terminals of a first latch and each of input terminals of a second latch and each of output terminals of the second latch and each of input terminals of a third latch based on the second control signal, and cross-connect each of the output terminals of the first latch and each of the input terminals of the second latch and each of the output terminals of the second latch and each of the input terminals of the third latch based on the second control signal.