| 摘要 |
PURPOSE: A column redundancy circuit of semiconductor memory device is provided to obtain a higher yield by replacing defective cells by one input/output unit, reduce a redundancy cell area, and reduce a memory chip size. CONSTITUTION: A memory cell array(100) includes a normal column memory cell block(120), which has a plurality of normal memory cells arranged in a matrix of rows and columns and normal column decoders, and a redundancy memory cell block(110), which has a redundancy column memory cell and a redundancy column decoder. A redundancy sense amplifier and write driver(210) is connected so as to correspond to the redundancy column memory block through a data bus. Normal sense amplifier and write drivers(220) are connected so as to correspond to the normal column memory cells through the data bus, respectively. The first redundancy column pre-decoders(250) generates a cutting output signal by cutting program fuses according to a column address when a defective cell is detected. The second redundancy column pre-decoder(230) is connected between the redundancy sense amplifier and write driver and the first redundancy column pre-decoder. The second redundancy column pre-decoder enable the redundancy sense amplifier and write driver when the first redundancy column pre-decoder is programmed, and outputs data of a corresponding redundancy cell through a redundancy data path. An input/output control circuit(240) is connected to correspond to each normal sense amplifier and write driver and uses an output of the first redundancy column pre-decoder as an input. The input/output control circuit disables a normal sense amplifier and write driver corresponding to a defective cell to connect a normal data path and a redundancy data path.
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