Patent ID: 7616514

Claim:
An apparatus for providing a reference voltage for reading data stored in a ferroelectric memory cell, the apparatus comprising: a set of reference cells, including a ferroelectric capacitor and an access switch, for storing data of a first logic state as a reference voltage during an active mode that occurs after the ferroelectric memory cell is selected to be read; and a reference voltage controller for writing data of a second logic state opposite to the first logic state, into the set of reference cells, in a stand-by mode that occurs before the ferroelectric memory cell is selected to be reads, wherein the set of reference cells include a first reference cell for providing a voltage corresponding to a non-switching capacitance, the first reference cell receiving a first control signal at a gate of a first control transistor and receiving a reference word line enable signal at a first access transistor, and a second reference cell for providing a voltage corresponding to a switching capacitance, the second reference cell receiving a second control signal at a gate of a second control switch transistor and receiving the reference word line enable signal at a second access transistor, wherein the first control transistor and the first access transistor are connected to one terminal of the first reference cell and the second control switch transistor and the second access transistor are connected to one terminal of the second reference cell and wherein the first control signal, received at the gate of the first control transistor, and the second control signal, received at the gate of the second control switch transistor, are independent.