Abstract: An apparatus for sensing a current direction of an input signal and amplifying the sensed input signal to a logic level in use for semiconductor memory devices includes a current-direction sensing ad amplifying means for sensing a current direction of the input signal and amplifying the input signal in response to a sensing control signal to output a sensed and amplified signal, and a voltage level shift means for receiving a reference voltage from an external circuit and shifting a voltage level of the sensed and amplified signal to output a level shifted signal, thereby preventing an erroneous operation therein and improving a data access time.