REDUNDANCY APPARATUS OF SEMICONDUCTOR MEMORY DEVICE

摘要

PURPOSE: A redundancy apparatus of a semiconductor memory device is provided to prevent the skew due to the length difference between a normal IO(input/output) line and a redundant IO line. CONSTITUTION: A redundancy apparatus of a semiconductor memory device includes a normal IO(input/output) line(110), a redundant IO line(120), an IO sense amplifier(130), a pair of multiplexers(150,160). The normal IO line(110) arranged at the cell array unit includes an IO line and an IOB(input/output bar) line. The redundant IO line(120) arranged at one side edge of the normal IO line(110) includes a RIO(redundant input/output) line replace with during the failure of the normal IO line(110) and a RIOB(redundant input/output bar) line. The IO sense amplifier(130) connected between the normal IO line(110) and the IOB line senses the voltage difference between the IO line and the IOB line to amplify the sensed voltage. The output of the IO sense amplifier(130) and the output of the RIO sense amplifier are inputted to the pair of multiplexers(150,160). The pair of multiplexers(150,160) read the data by selecting the output of the IO sense amplifier(130) when the normal IO line(110) is normal and by selecting the output of the RIO sense amplifier when the normal IO line(110) is fail. The redundancy apparatus is characterized in that the distance between the normal IO line(110) and the IO sense amplifier(130) is equal to that of the redundant IO line and the RIO sense amplifier.