Graphical analysis of the I-V characteristics of generalized p-n-p-n devices

A new form of the basic equation for the I-V characteristics of a generalized p-n-p-n device is derived. Approximations are then introduced to obtain a simplified basic equation in which all current-dependent terms appear on one side of the equation and all voltage-dependent terms on the other. A graphical technique for solving the simplified device equation is then described and used to develop and illuminate the family resemblance among a large number of related p-n junction devices; viz., the p-n junction diode, the p-n-p diode, the p-n-p transistor, the p-n-p-n diode, and the p-n-p-n triode.