Darlington analysis of dynamic current exchanges

The Darlington, a bipolar cascade, is the site of complex current exchanges between the pilot and the main transistor which determine the reliability and possible range of frequencies of this switch. An analysis using both soft modelling and experimentation has provided evidence of the mechanisms inducing these exchanges. These observations provide a basis for developing base drive circuits to extend the frequency range of the component. This paper deals with the experimental part of studies on Darlington and proposes new base drive circuits