Data output circuit capable of controlling the output time of external output data signal in semiconductor memory device according to variations of external power supply voltage

摘要

PURPOSE: A data output circuit of semiconductor memory device capable of adjusting output timing of an external output data signal according to variation of external power supply voltage is provided, which is capable of adjusting an output point of time of an external output data according to variation of an external power supply voltage. CONSTITUTION: A synchronization part(220) synchronizes an internal output data signal and an inverted version of the internal output data signal to a clock signal and outputs the first to fourth internal output data signals. The first delay part(250) generates the first delay control signal for controlling a delay of the third internal output data signal in response to the first internal output data signal and variation of an external power supply voltage. The second delay part(270) generates the second delay control signal for controlling delay of the fourth internal output data signal in response to the second internal output data signal and the variation of an external power supply voltage. A latch part(230) latches the third and fourth internal output data signals and outputs the fifth and sixth internal output data signals. A driver part(240) outputs an external output data signal in response to the fifth and sixth internal output data signals.