Multimode data buffer and method for controlling propagation delay time

PURPOSE: A multi mode data buffer controlling propagation delay time and control method thereof are provided to control propagation delay time by actually equalizing setup/hold time at a SM mode to setup/hold time at a DM mode. CONSTITUTION: At least two switches(211,212) pass an inverted data strobe signal or a reference voltage respectively according to a level of a control signal. And a differential amplifier circuit(21) comprises a differential amplifier(213) receiving a data strobe signal and the above inverted data strobe signal or the above reference voltage and outputting a differential amplification signal. The above differential amplification signal is transmitted to output ports as at least two data strobe signals through two transmission paths in response to the above control signal.