US 6,487,109 B2Granted

Magnetoresistive memory and method for reading a magnetoresistive memory

AssigneeInfineon Technologies AG

InventorsRoland Thewes, Werner Weber, Hugo Van Den Berg

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Abstract

A magnetoresistive memory includes magnetoresistive memory cells disposed in a plurality of rows and/or columns. A bit line is connected to first poles of the memory cells of a column. A word line is connected to second poles of the memory cells of a row. A read voltage source is separately connectable to first ends of the word lines. A voltage evaluator has at least one input that is separately connectable to first ends of the bit lines via an evaluation line. A first terminating resistor branches from the evaluation line. An impedance converter has an input connected to the evaluation line and has an output separately connectable to second ends of the bit lines and word lines. The invention also relates to a method of reading magnetoresistive memories.

Claims22

Dependent claims

A magnetoresistive memory, comprising:

magnetoresistive memory cells having respective first poles and second poles and being disposed in an array formed by rows and columns;
bit lines assigned to said columns, said bit lines being connected to said first poles of said magnetoresistive memory cells disposed in associated ones of the columns, said bit lines having first ends and second ends;
word lines assigned to said rows, said word lines being connected to said second poles of said magnetoresistive memory cells disposed in associated ones of the rows, said word lines having first ends and second ends;
a read voltage source;
first switching elements connected such that said read voltage source is separately connectable to said first ends of said word lines via said first switching elements;
an evaluation line;
second switching elements;
a voltage evaluator having at least one input, said at least one input being separately connectable, via said evaluation line, to said first ends of said bit lines by said second switching elements;
a first terminating resistor branching from said evaluation line;
third switching elements;
and
an impedance converter having an input connected to said evaluation line and having an output separately connectable to said second ends of said bit lines and said word lines with said third switching elements.

9 more elements

A method for reading magnetoresistive memory cells in a magnetoresistive memory including an array of magnetoresistive memory cells respectively disposed in a plurality of rows and a plurality of columns, the magnetoresistive memory further including a bit line for each of the columns, the bit line being connected to first poles of the magnetoresistive memory cells belonging to a respective column, and the magnetoresistive memory further including a word line for each of the rows, the word line being connected to second poles of the magnetoresistive memory cells belonging to a respective row, the method which comprises the following steps:

step A) connecting a read voltage source to a second pole of a magnetoresistive memory cell to be read;
step B) evaluating a voltage, which drops across a first terminating resistor, with a voltage evaluator, with the first terminating resistor and a first input of the voltage evaluator being connected to a first pole of the magnetoresistive memory cell to be read;
and
step C) applying the voltage, which drops across the first terminating resistor, also to an input of an impedance converter, and applying a voltage at an output of the impedance converter to word lines and bit lines not connected to the magnetoresistive memory cell to be read.

1 more element

Dependencies are inferred from the claim text.