US Patent 7099177 Nonvolatile ferroelectric memory device having power control function

A nonvolatile ferroelectric memory device having a power control function improves a sensing margin by stably controlling a power applied to a cell capacitor. In the nonvolatile ferroelectric memory device, an operating voltage of the cell is controlled depending on an external supply voltage in order to apply the highest voltage to the cell capacitor, and a power voltage obtained by dropping an external power voltage is applied to adjacent circuits in order to apply a lower voltage to adjacent circuits. Additionally, different ESD (Electro Static Discharge) circuits for performing an electrostatic discharge function in an input/output unit are embodied depending on the supplied voltage level, thereby stabilizing power.