Data retention circuit and semiconductor memory device using the same
First Claim
1. A semiconductor memory device comprising:
- a memory means having a plurality of memory cells, each memory cell including a flip-flop circuit having driver transistors; and
a threshold voltage control means for controlling respective threshold voltages of said driver transistors,said threshold voltage control means controlling at least each threshold voltage of driver transistors constituting a selected memory cell to be a first threshold voltage when said memory device is in an accessed state of the memory device, and said threshold voltage control means controlling threshold voltages of all of respective driver transistors constituting each memory cell to be a second threshold voltage different from said first threshold voltage when said memory device is in a stand-by state of the memory device.
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Accused Products
Abstract
A semiconductor memory device includes a memory unit having a plurality of memory cells. Each memory cell includes a flip-flop circuit having driver transistors, as a data retention circuit. The device further includes a threshold voltage control unit for controlling respective threshold voltages of the driver transistors. When the device is in its accessed state, the threshold voltage control unit controls at least each threshold voltage of driver transistors constituting a selected memory cell to be a first threshold voltage. When the device is in its stand-by state, the threshold voltage control unit controls threshold voltages of all of respective driver transistors constituting each memory cell to be a second threshold voltage different from the first threshold voltage. By the constitution, it is possible to realize a stable data retention operation under the condition of a lower power supply voltage, and to reduce a dissipated power in a stand-by state.
97 Citations
8 Claims
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1. A semiconductor memory device comprising:
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a memory means having a plurality of memory cells, each memory cell including a flip-flop circuit having driver transistors; and a threshold voltage control means for controlling respective threshold voltages of said driver transistors, said threshold voltage control means controlling at least each threshold voltage of driver transistors constituting a selected memory cell to be a first threshold voltage when said memory device is in an accessed state of the memory device, and said threshold voltage control means controlling threshold voltages of all of respective driver transistors constituting each memory cell to be a second threshold voltage different from said first threshold voltage when said memory device is in a stand-by state of the memory device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification