Sense circuit for reading data stored in nonvolatile memory cells

DETAILED DESCRIPTION There is a need for a sense circuit which although possessing static operating characteristics comparable to the static operating characteristics of a current-offset type circuit or anyway having a wide operating range toward the maximum supply voltage (VCC.
sub.
max) also possess improved dynamic characteristics as compared to a current-offset circuit of the known type.
This objective is reached by means of the current-offset sense circuit which forms the object of the present invention.
Basically, the device for generating an unbalance between a reference cell branch of the sense circuit and another branch of the circuit comprising the selectively addressed array cell to be read, which is employed is basically a current generator and therefore, as in the case of a currentoffset sense circuit of the prior art, the sizes of the load transistors of the array side and of the reference side of the differential sense circuit are advantageously identical, thus avoiding the above mentioned drawbacks typical of a load-unbalance sense circuit.
The circuit is driven essentially by the same gate voltage which is present on the array cells and for this purpose it is necessary to introduce in the array of cells a supplementary row which is decoded at every reading, and which replicates during transients the behaviour of the array's row which is selected for reading.