The effect of collector resistance upon the high current capability of n-p-ν-n transistors

It is shown that the onset of conductivity modulation of the bulk collector resistance causes an abrupt decrease in h
FE
at high current density and consequently limits the current range in which a transistor exhibits usable gain. Data are presented which demonstrate the accurate measurement of equilibrium collector resistance from a curve-tracer display. Experimental results showing the effect of partial saturation upon transistor switching time are also presented. Recognition of this phenomenon suggests a reappraisal of the importance of other potential causes of high current h
FE
decrease.