Patent ID: 8174594

Claim:
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, and each of the up/down ripple counters includes, a latch having an input terminal, output terminal and complementary output terminal and clock terminal; and a switch block configured to connect one of the output terminal and the complementary output terminal of the latch to the input terminal of the latch in response to the corresponding one of the operation control signals, connect one of an output terminal and a complementary output terminal of a preceding latch to a clock terminal of the latch in response to the second control signal, and connect one of the output terminal and the complementary output terminal of the latch to a clock terminal of a next latch in response to the second control signal.