Patent ID: 7995415
Filing Date: 2011-08-09
Classification: G11C

Abstract:
1. A method of operating a dynamic random access memory device having an array of memory cells that require periodic refresh, each of the memory cells including a memory cell capacitor formed by a cell plate that is common to the capacitors of a plurality of memory cells, the method comprising: in a first operating mode, biasing the cell plate to a first voltage; after switching the memory device from operation in the first mode to operation in a refresh mode, biasing the cell plate to a second voltage that is different from the first voltage; in the refresh mode, periodically refreshing the memory cells in the array during a refresh period interspersed with a quiescent period in which none of the memory cells in the array are being refreshed; in the refresh mode, biasing the cell plate to the second voltage during the quiescent period; in the refresh mode, biasing the cell plate to the first voltage during the refresh period; and after switching the memory device from operation in the refresh mode to operation in the first mode, biasing the cell plate to the first voltage.