METHOD AND DEVICE FOR REFRESHING SEMICONDUCTOR MEMORY

摘要

PURPOSE: A device for refreshing a semiconductor memory is provided to refresh all memory cells by pumping a voltage of a cell capacitor plate according to a constant refresh rate only one times. CONSTITUTION: A refresh device of a semiconductor memory comprises a charge pump which is connected to a cell plate line(a) supplied with a cell plate voltage. The charge pump is composed of a resistor and a PMOS transistor connected in series between a power supply voltage and the cell plate line(a). The PMOS transistor is turned on and off according to an oscillation control signal. Or, the charge pump is composed of four PMOS transistors. A first and a second PMOS transistors have a current electrode connected to the cell plate line(a), respectively. The first PMOS transistor has a gate connected to the other current electrode of the second PMOS transistor and to a gate of a third PMOS transistor, and the second PMOS transistor has a gate connected to the other current electrode of the first PMOS transistor and to a gate of a fourth PMOS transistor. Both current electrodes of each of the third and fourth PMOS transistors are connected to receive an oscillation control signal in common.