US Patent 7499370 Synchronous semiconductor memory device

A synchronous semiconductor memory device includes an output control signal generator, which generates an output control signal corresponding to a signal obtained by delaying a read information signal in response to a delay internal clock signal obtained by dividing an internal clock signal by n, first and second sampling signals obtained by delaying the internal clock signal, a first output control clock signal obtained by dividing the internal clock signal by n, and a column address strobe (CAS) latency signal. The synchronous semiconductor memory device also includes a data output buffer, which outputs data by buffering internal data in response to the output control signal and the first output control clock signal.