ACCURATE AND ROBUST + -NV(T) EXTRACTOR

An accurate and robust +/-nV(T) extractor is introduced. Basically, th e circuit consists of a current comparator and a source follower. The output of the comparator controls the bias current level in the follow er, and thus its low output resistance is divided by the loop gain pro viding high accuracy in most applications. Experimental results using commercial matched MOS transistor array TC4007, which have been compar ed with the value obtained by classical methods, confirm the validity of the proposed circuit.