Method for self-terminated writing with quasi-constant voltage across resistive-type memory element and circuit thereof

Abstract

A method for self-terminated writing with quasi-constant voltage drop across resistive-type memory cell is provided. The method comprises: creating a writing voltage and a writing current flowing through a resistive memory cell; reproducing the writing current to generate a reproduced writing current; flowing the reproduced writing current through a dummy circuit to generate a dummy writing voltage; adding the dummy writing voltage and a reference voltage to generate a reference writing voltage, wherein the dummy writing voltage slightly and proportionally increases during writing; and adjusting the writing voltage and the writing current according to the reference writing voltage so that a voltage drop across the resistive memory cell keeps constant or slightly increases during writing. When the reproduced writing current reaches a predetermined target current value, a termination signal is issued. The termination signal turns off the related writing circuits to optimize the writing period of the resistive-type memory cell.