A method for determination of the dc characteristics of an n-p-n-p structure is described. Each of the three diffused regions is first of all characterized by computer analysis using the variable boundary regional approach at one low-bias value (mobility variation with doping level and high doping bandgap reduction effects are included in this program). A set of constants thus obtained is used to define a set of simplified analytic

relations for each of the four regions. These analytic relations are solved using an elementary program to predict the

characteristics. Experimental and computed results are included for normal and gold-doped devices and explanations for operation with extreme (low- and high-) lifetime values are given.