Circuit for high-precision analog reading of nonvolatile memory cells, in particular analog or multilevel flash or EEPROM memory cells

摘要

An analog read circuit includes an output transistor connected to a memory cell to be read, and an operational amplifier having a non- inverting input connected to the drain terminal of the memory cell, an inverting input connected to a reference terminal, and an output, forming the output of the reading circuit and connected to the gate terminal of the output transistor. Bias transistors maintain the memory cell and the output transistor in the linear region, and the operational amplifier and the output transistor form a negative feedback loop so that the output voltage V.sub.O of the read circuit is linerly dependent upon the threshold voltage the memory cell. The reading circuit has high precision and high reading speed.