Current drive circuit avoiding effect of voltage drop caused by load and semiconductor memory device equipped therewith
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorTsukasa Ooishi
Life of this patent
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Abstract
A current drive circuit operates receiving higher voltage than in a waiting mode at source terminal of a P-channel first driver transistor, when supplying a current to a node connected to a load circuit. In accordance with the rising source potential of the first driver transistor, the gate potential output to the first driver transistor by a gate potential control circuit rises. When the first and second driver transistors are off, a precharge circuit configured with a P-channel MOS transistor precharges the node to a prescribed potential. As a result, the current drive circuit is provided with increased reliability of the gate insulating films of the driver transistors without decreasing the driving current.
Claims16
A current drive circuit passing a current through a load circuit with resistance, comprising:
- a node connected to said load circuit;
- and
- a driver receiving a first voltage and a second voltage;
- wherein
- a voltage difference between said second voltage and a voltage on said node is larger than said first voltage;
- and
- said driver passes a current through said node in accordance with said voltage difference.
A semiconductor memory device, comprising:
- a plurality of memory cells arranged in rows and columns;
- a plurality of bit lines provided corresponding to each column of memory cells;
- and
- a plurality of current drive circuits provided corresponding to said plurality of bit lines, passing a current through corresponding bit line;
- wherein
- each of said plurality of current drive circuits receives a first voltage and a second voltage, a voltage difference between said second voltage and a voltage on said corresponding bit line is larger than said first voltage, and each of said plurality of current drive circuits passes a current through said corresponding bit line in accordance with said voltage difference.
Dependencies are inferred from the claim text.