US 9,286,218 B2 · Word line auto-booting in a spin-torque magnetic memory having local source lines

Abstract

In a spin-torque magnetic random access memory (MRAM) that includes local source lines, auto-booting of the word line is used to conserve power consumption by reusing charge already present from driving a plurality of bit lines during writing operations. Auto-booting is accomplished by first driving the word line to a first word line voltage. After such driving, the word line isolated. Subsequent driving of the plurality of bit lines that are capacitively coupled to the word line causes the word line voltage to be increased to a level desired to allow sufficient current to flow through a selected memory cell to write information into the selected memory cell. Additional embodiments include the use of a supplemental voltage provider that is able to further boost or hold the isolated word line at the needed voltage level.

Claims22

Dependent claims

A method for accessing a selected memory cell in a magnetic memory, comprising:

driving a word line to a first word line voltage, wherein the word line is coupled to a set of selection transistors, wherein each selection transistor of the set of selection transistors is coupled between a first electrode of a corresponding memory cell of a set of memory cells and a source line shared by the set of memory cells, wherein the selected memory cell is included in the set of memory cells;
isolating the word line from circuitry used to drive the word line to the first word line voltage to produce an isolated word line;
and
driving a plurality of bit lines to a first bit line voltage, wherein each bit line of the plurality of bit lines is coupled to a second electrode of a corresponding memory cell of the set of memory cells, wherein the first bit line voltage is different than the first word line voltage, and wherein driving the plurality of bit lines to the first bit line voltage adjusts voltage on the isolated word line to a second word line voltage.

1 more element

A method for accessing a selected memory cell in a magnetic memory, comprising:

driving a word line to a first word line voltage, wherein the word line is coupled to a set of selection transistors, wherein each selection transistor of the set of selection transistors is coupled between a first electrode of a corresponding memory cell of a set of memory cells and a source line shared by the set of memory cells, wherein the selected memory cell is included in the set of memory cells;
isolating the word line from circuitry used to drive the word line to the first word line voltage to produce an isolated word line;
enabling a supplemental voltage provider to adjust a voltage level on the isolated word line to a second word line voltage;
and
driving a plurality of bit lines to a first bit line voltage, wherein each bit line of the plurality of bit lines is coupled to a first electrode of a corresponding memory cell of the set of memory cells, wherein the first bit line voltage is different than the first word line voltage, and wherein driving the plurality of bit lines to the first bit line voltage changes the voltage level on the isolated word line to a third word line voltage.

2 more elements

Dependencies are inferred from the claim text.

Word line auto-booting in a spin-torque magnetic memory having local source lines

Life of this patent

Word line auto-booting in a spin-torque magnetic memory having local source lines

Life of this patent

Abstract

Claims22