Redundancy circuit in semiconductor memory device having a multiblock structure
View Patent ↗A redundancy circuit in a semiconductor memory device having a multiblock structure in which a memory cell array is classified into a plurality of memory cell blocks, an integrated redundancy circuit having a plurality of fuse boxes for storing, per block, addresses of defective memory cells provided in the plurality of memory cell blocks, the plurality of fuse boxes being connected to the common precharge unit and being selectively activated in response to a block distinction selection signal.
1. A redundancy circuit in a semiconductor memory device having a multiblock structure in which a memory cell array is classified into a plurality of memory cell blocks, the circuit comprising:
a common precharge unit; and
an integrated redundancy circuit having a plurality of fuse boxes for storing addresses of defective memory cells per memory cell block provided in the plurality of memory cell blocks, the plurality of fuse boxes being connected to the common precharge unit through block switches selectively activated in response to a block distinction selection signal.
2. The circuit as claimed in claim 1 , wherein the number of fuse boxes is equal to the number of memory cell blocks.
3. The circuit as claimed in claim 1 , wherein the fuse boxes comprise:
fuses that are integrated for multiple memory cell blocks.
4. The circuit as claimed in claim 1 wherein the integrated redundancy circuit is a single circuit providing redundancy to the plurality of memory cell blocks.
5. A semiconductor memory device having substitute memory cells for defective memory cells, the semiconductor memory device comprising:
a plurality of memory cell blocks including a plurality of non-defective memory cells and a plurality of the defective memory cells;
a plurality of the substitute memory cells;
an addressing mechanism for addressing the substitute memory cells instead of the defective memory cells in the semiconductor memory device; and
a single redundancy circuit for providing redundancy by operatively substituting the defective memory cells with the substitute memory cells using the addressing mechanism,
wherein the single redundancy circuit has a plurality of fuse boxes for storing addresses of the defective memory cells per memory cell block provided in the plurality of memory cell blocks, the plurality of fuse boxes being connected to a common precharge unit through block switches for selectively connecting the precharge node to a given one of the fuse boxes, selectively activated in response to a block distinction selection signal.
6. The semiconductor memory device of claim 5 wherein the single redundancy circuit using the fuse boxes is being used to address said substitute memory cells in place of the defective memory cells.
7. The semiconductor memory device of claim 5 wherein the single redundancy circuit further comprises:
a precharge node that is precharged by the common precharge unit at a predetermined voltage level in response to a redundancy signal.
8. The semiconductor memory device of claim 7 further comprising:
a pass transistor array for changing a voltage level of the precharge node in conformity with a fuse programming in response to a redundancy address;
a state sustainable circuit for maintaining the voltage level of the precharge node during a redundancy operating mode; and
a redundancy enable signal generating circuit for commonly receiving output logic levels of the state sustainable circuit through one input terminal thereof, and individually receiving block redundancy addresses through another input terminal thereof, to generate a redundancy enable signal per memory cell block.
9. The semiconductor memory device of claim 5 wherein the single redundancy circuit is used to provide redundancy for the defective memory cells in the plurality of memory cell blocks.
10. A semiconductor memory device, comprising:
a memory cell array comprised of a plurality of memory cell blocks;
a common precharge unit for precharging a precharge node by a predetermined voltage level in response to a redundancy signal;
a plurality of fuse boxes grouped by numbers corresponding to the memory cell blocks;
a block switch for selectively connecting the precharge node to at least one of the plurality of fuse boxes in response to a block redundancy addressing signal;
a pass transistor array for changing a voltage level of the precharge node in conformity with a fuse programming in response to a redundancy address;
a state sustainable circuit for maintaining the voltage level of the precharge node during a redundancy operating mode; and
a redundancy enable signal generating circuit for commonly receiving output logic levels of the state sustainable circuit through one input terminal thereof, and individually receiving block redundancy addresses through another input terminal thereof, to generate a redundancy enable signal per memory cell block.
11. A method of providing redundant memory cells to operatively substitute defective memory cells in a semiconductor memory device, the method comprising:
providing a common precharge unit;
providing an integrated redundancy circuit having a plurality of fuse boxes for storing addresses of the defective memory cells per memory cell block provided in a plurality of memory cell blocks, the plurality of fuse boxes being connected to the common precharge unit; and
selectively activating the fuse boxes through block switches in response to a block distinction selection signal.
12. The method of claim 11 further comprising:
addressing a redundant memory cell through the integrated redundancy circuit to operatively substitute the defective memory cells in the semiconductor memory device.
13. The method of claim 11 further comprising:
providing substitute memory cells that are addressed through the fuse boxes in response to the block distinction selection signal to operatively substitute the defective memory cells.