Method and device for improved magnetic field generation during a write operation of a magnetoresistive memory device
View Patent ↗Magnetic or magnetoresistive random access memories (MRAMs) are implemented in a variety of arrangements and methods. Using one such arrangement, a matrix is implemented with magnetoresistive memory cells logically organized in rows and columns, each memory cell including a magnetoresistive element. The matrix has a set of column lines, a column line being a continuous conductive strip which is magnetically coupled to the magnetoresistive element of each of the memory cells of a column, wherein each column line has a forward column line and a return column line arranged on opposite sides of the magnetoresistive element and offset from one another for forming a return path for current in that column line.
1. A matrix with magnetoresistive memory cells logically organized in rows and columns, each memory cell including a magnetoresistive element, the matrix comprising a set of column lines, a column line being a continuous conductive strip which is magnetically coupled to the magnetoresistive element of each of the memory cells of a column, wherein each column line has a forward column line and a return column line arranged on opposite sides of the magnetoresistive element and offset from one another for forming a return path for current in that column line and for altering a magnetic field at a selected magnetoresistive element and generated by current flow in the column line for writing to the selected magnetoresistive element.
2. A matrix according to claim 1 , further comprising a set of row lines, a row line being a continuous conductive strip which is magnetically coupled to the magnetoresistive clement of each of the memory cells of a row.
3. A matrix according to claim 2 , wherein each row line has a forward row line and a return row line for forming a return path for current in that row line and for altering a magnetic field at the selected magnetoresistive element.
4. A matrix according to claim 2 , wherein for each row line, two adjacent row lines are used for forming a return path for current in that row line and for altering the magnetic field of a selected magnetoresistive element.
5. A matrix according to claim 4 , wherein the return row lines are provided with a flux guiding cladding layer.
6. A matrix according to claim 2 , wherein the row lines are provided with a flux guiding cladding layer.
7. A matrix according to claim 1 , wherein the column of magnetoresistive elements is placed offset in a row-direction with regard to the center of the column lines.
8. A matrix according to claim 1 , wherein the column of magnetoresistive elements is placed offset in a row-direction with regard to the center of the return column lines.
9. A matrix according to claim 1 , wherein the column of magnetoresistive elements is placed symmetrically with regard to both the column line and at least one return column line.
10. A matrix according to claim 1 , wherein the column lines or the return column lines are provided with a flux guiding cladding layer.
11. A matrix according to claim 1 , wherein the matrix is used as a nonvolatile memory array.
12. A method of writing a magnetoresistive element in a matrix of magnetoresistive memory elements arranged in logically organized rows and columns, comprising:
combining, in the magnetoresistive element, a magnetic field from a current line with a magnetic field from at least one return current line arranged on an opposite side of the magnetoresistive element and offset from the magnetoresistive element to thereby increase the magnetic field for writing to the magnetoresistive element.