Programming a RRAM method and apparatus
AssigneeCrossbar, Inc.
InventorsSang Thanh Nguyen, Hagop Nazarian, Layne Armijo
Life of this patent
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Abstract
A circuit for programming a resistive switching device includes a resistive switching device characterized by a programmable resistance, the resistive switching device comprising a first terminal, a second terminal, and a resistive switching element, a first circuit configured to supply a programming voltage to the resistive switching device and to supply a predetermined current to flow in the resistive switching device, and a second circuit coupled to the first circuit and to the resistive switching device, wherein the second circuit is configured to terminate the supply of the programming voltage to the resistive switching device when the predetermined current flows in the resistive switching device.
Claims20
A circuit coupled to a voltage source for programming a resistive switching device, comprising:
- a resistive switching device characterized by a programmable resistance, the resistive switching device comprising a first terminal, a second terminal, and a resistive switching element;
- a first circuit coupled to the voltage source, wherein the first circuit is configured to supply a programming voltage to the resistive switching device and to supply a predetermined current to flow in the resistive switching device in response to a voltage supplied by the voltage source;
- and
- a second circuit coupled to the first circuit and to the resistive switching device, wherein the second circuit is configured to terminate the supply of the programming voltage to the resistive switching device when the predetermined current flows in the resistive switching device, wherein the second circuit comprises a pair of cross-coupled PMOS transistors.
A method of programming a resistive switching device, comprising:
- providing a resistive switching device comprising a first electrode, a second electrode, and a resistive switching element characterized by a programmable electrical resistance between the first electrode and the second terminal;
- applying a programming voltage from a voltage source to the first electrode to cause a first current to flow in the resistive switching device comprising:
- activating a first PMOS transistor having a drain coupled to the voltage source;
- and
- switching a pair of cross-coupled PMOS transistors coupled to a source of the first PMOS transistor and to the first electrode of the resistive switching element to provide the programming voltage to the first terminal of the resistive switching device;
- and
- terminating the first current flowing into the resistive switching device when the first current is not less than a predetermined current comprising:
- determining when the first current is not less than the predetermined current;
- and
- switching the pair of cross-coupled PMOS transistors to terminate providing the programming voltage to the first terminal of the resistive switching device in response to determining the first current is not less than the predetermined current.
Dependencies are inferred from the claim text.