Method for precise determination of the statistical distribution of the input offset voltage of differential stages

A powerful method is presented that allows precise determination of the statistical distribution of the input offset voltage of differential pairs which are of prime importance for the accuracy of differential amplifiers. We use a specifically developed test structure with differential pairs arranged in large arrays. A number of layout variants typical for analog applications is realized. Measured data are shown to demonstrate the high performance of the proposed method. On the basis of matching results from this method valuable information is obtained for optimizing analog circuit design.