Digital-to-analogue converter and neuromorphic circuit using such a converter

Abstract

A digital-to-analogue converter, with application to electronic circuits with neuromorphic architecture, comprises: transistors of identical nominal geometrical characteristics, but of dispersed current-voltage characteristics, wherein when a constant gate-source voltage is applied to the different transistors, a current varying as a function of the dispersion circulates in the transistor; a digital table receiving a digital word and having a selection output selecting, as a function of the word to be converted, a transistor or transistors supplying a current of desired value representing this word in analogue form. The look-up table is loaded as a function of real measured current-voltage characteristics of different transistors of the set, to establish a look-up between words and current values. The wide variability of characteristics of the transistors, notably their leakage current for a gate-source voltage below the switch-on threshold, allows finding combinations of leakage currents which are a good representation of words to be converted.