Apparatus and method for an active field plate bias generator

摘要

The plate voltage for a Dynamic Random Access Memory storage cell array is provided by two amplifiers. The first amplifier operates at a relatively low power level and compensates for leakage in the storage cell array, the compensation initiated by a departure of the plate from a nominal value which exceeds a preselected amount. The second amplifier operates at a higher power level and provides compensation for transients in the plate voltage resulting from the charging and discharging of the storage cells. Because the transients occur when the storage cells are accessed, the second amplifier is enabled only when a group of storage cells is accessed. In addition to operating at a higher power level, the second amplifier is more sensitive and responds to smaller excursions from the nominal voltage. Both the first and the second amplifiers have separate driver circuits for responding to excursions above and for responding to excursions below the nominal voltage.