Data reading method for memory cell and sensitive amplifier used for multi-level cell (MLC)

Abstract

The invention provides a data reading method for a memory cell and a sensitive amplifier used for a multi-level cell (MLC) flash memory. The method comprises the following steps: carrying out primary reading, applying read voltages to the memory cell and a first reference unit, and converting the current generated by the memory unit and the first reference unit into voltages; comparing the voltages of the two; if the preset condition is satisfied, judging the data state of the memory cell, and if not, carrying out secondary reading; lifting or reducing the read voltages applied to the memory cell and the residue (2n-2) numbered reference units except for the first reference unit according to the preset condition, and converting the current generated by the memory cell and the residue (2n-2) numbered reference units into voltages; comparing the voltages of the memory cell and the reference units and judging the data state of the memory cell; and finally outputting data information according to the judged data state. In the invention, the current variation range is small, and the difference between the obtained voltages is relatively stable, thus the data state can be accurately recognized, and the method of the invention has the advantage of reducing the reading time compared with the serial reading method.

Description

Technical field [0001] The present invention relates to the technical field of integrated circuit memory, in particular to a method for reading the state of a memory cell and a sensitive amplifier for multi-layer cell flash memory. Background technique [0002] A sense amplifier is a very important circuit in a memory device. It is mainly used to identify the state of data bits stored in a memory cell to convert it into a digital signal; the sense amplifier is very critical to the performance of the memory. [0003] Specifically, because the difference between the different states of the data bits in the memory cell is small, the Sense amplifier needs to overcome the noise and interference to identify the difference between the different states, thereby completing the data reading. Therefore, whether the Sense amplifier can well recognize various state differences will directly affect the performance of the memory. Secondly, the speed of the Sense amplifier will also greatly affec...

AI Technical Summary

Problems solved by technology

However, a three-step read takes three times as long as a single read, significantly slowing down reads compared to parallel reads

Images