Magnetoelectronic memory element with inductively coupled write wires
View Patent ↗The magnetization state of a ferromagnetic layer can be set to correspond to different values of a data item to be stored in a hybrid memory device. The magnetization state is non-volatile, and a write circuit can be coupled to the ferromagnetic layer to reset or change the magnetization state to a different value. The write circuit uses a pair of inductively coupled write wires in each row and column, which are each given a signal with an amplitude approximately ½ of that required to change the state of the ferromagnetic layer.
1. An electronic device comprising:
a first semiconductive material capable of conducting an electrical current; and
a second ferromagnetic material with a magnetization state that is magnetically coupled to a portion of the first semiconductive material; and
an isolation element coupled to the first semiconductive material for isolating such first semiconductive material; and
a first thin film write line inductively coupled to a first portion of said second ferromagnetic material; and
a second thin film write line inductively coupled to a second portion of said second ferromagnetic material;
wherein at least one of said first thin film write line and said second thin film write line are also part of a read circuit;
wherein said magnetization state is not alterable in response to a single write pulse presented on only one of said first and second write lines.
2. The device of claim 1 , wherein an electrical signal can be generated as an output from the first material based on the magnetic coupling, and the isolation element is coupled to and isolates such output.
3. The device of claim 2 , further including a sensing circuit for receiving the electrical signal from the isolation element.
4. The device of claim 3 , wherein the magnetization state corresponds to a data value, and the data value can be determined from the electrical signal received by the sensing circuit.
5. The device of claim 4 , further including a bias source coupled to the first material for generating the electrical current.
6. The device of claim 5 , wherein the isolation element includes a transistor, and the sensing circuit receives the electrical signal in response to a select signal applied to the transistor.
7. The device of claim 5 , wherein the isolation element is a diode, resistor or capacitor, and the sensing circuit receives the electrical signal in response to a select signal applied to the first material.
8. The device of claim 1 , further including a write circuit for setting the magnetization state of the ferromagnetic layer.
9. The memory circuit of claim 1 , wherein the magnetization state of the ferromagnetic material is configurable and non-volatile.
10. A memory circuit for storing a data value comprising:
a magnetoelectronic element situated on a semiconductor material, said magnetoelectronic element having at least one thin film ferromagnetic layer with a magnetization state oriented in a plane of such ferromagnetic layer and corresponding to the data value; and
a first thin film write line inductively coupled to said thin film ferromagnetic layer; and
a second thin film write line inductively coupled to said thin film ferromagnetic layer; and
said first and second write lines being arranged with respect to the thin film ferromagnetic layer such that a write signal can be carried by said first and second write lines to generate a magnetic field that sufficient to alter said magnetization state;
a CMOS sense amplifier circuit coupled to an output of the magnetoelectronic element for determining whether said data value is a first value or a second value;
wherein the magnetoelectronic element does not include a separate semiconductor select transistor for reading said data value.
11. The memory circuit of claim 10 , wherein said write signal is configured so that when present on said first or second write lines it generates a magnetic field having a coercivity that is greater than ½ of that of the ferromagnetic layer.
12. The memory circuit of claim 10 , wherein a first write signal on said first write line and a second write signal on said second write line are required at the same time to alter said magnetization state.
13. The memory circuit of claim 10 , wherein at least one of said first or second write line are also used as a read line.
14. The memory circuit of claim 10 , wherein a bias signal is applied and maintained to said magnetoelectronic element to increase a data read speed.
15. The memory circuit of claim 10 , further including a semiconductor isolation element for isolating said magnetoelectronic element from other magnetoelectronic elements, which isolation element includes a semiconductor select transistor which responds to a select signal for reading said data value from the memory circuit.
16. A hybrid semiconductor-magnetic memory array for storing non-volatile data comprising:
a plurality of thin film magnetic memory cells located on a semiconductor material, each having at least one first single thin film ferromagnetic layer with an alterable magnetization state oriented in a plane of such thin film ferromagnetic layer, said alterable magnetization state representing a plurality of respective non-volatile data values; and
a first thin film write line inductively coupled to said first single thin film ferromagnetic layer;
a second thin film write line inductively coupled to said first single thin film ferromagnetic layer;
wherein each of said plurality of thin film magnetic memory cells is configured such that their respective data values are not alterable unless a first write signal and a second write signal are present on said first and second write lines respectively at the same time;
a plurality of semiconductor isolation elements for isolating said plurality of thin film magnetic memory cells from each other, which plurality of semiconductor isolation elements respond to a select signal for reading a non-volatile data value from said plurality of thin film magnetic memory cells and which are configured in the hybrid semiconductor-magnetic memory array so that each of said plurality of thin film magnetic memory cells magnetic cells has at most one isolation element.
17. The hybrid semiconductor-magnetic memory array memory circuit of claim 16 , wherein said plurality of thin film magnetic memory cells each include a hybrid hall effect device.
18. The memory circuit of claim 10 , wherein a bias signal is applied and maintained to the array data lines to increase a data read speed.
19. The hybrid semiconductor-magnetic memory array of claim 16 wherein said plurality of semiconductor isolation elements are field effect transistors.
20. The hybrid semiconductor-magnetic memory array of claim 16 wherein said plurality of semiconductor isolation elements are thin film devices.
21. The hybrid semiconductor-magnetic memory array of claim 16 , further including a single voltage polarity power supply for supplying operating voltages to said plurality of magnetoelectronic memory cells.