Editing Gummel plot (section)

[[File:SiGe HBT Gummel Plot.png|thumb|SiGe HBT Gummel plot]]
In [[electronics]], the '''Gummel plot''' is the combined plot of the base and collector [[electric current]]s, <math>I_\text{c}</math> and <math>I_\text{b}</math>, of a [[Bipolar junction transistor|bipolar transistor]] vs. the base–emitter [[voltage]], <math>V_\text{be}</math>, on a semi-[[logarithmic scale]]. This plot is very useful in device characterization because it reflects on the quality of the emitter–base [[Junction (semiconductor)|junction]] while the base–collector bias, <math>V_\text{bc}</math>, is kept [[Constant (mathematics)|constant]].

A number of other device parameters can be garnered either [[Quantitative property|quantitatively]] or [[qualitative data|qualitatively]] directly from the Gummel plot:<ref>A. S. Zoolfakar et N. A. Shahrol, «Modelling of NPN Bipolar Junction Transistor Characteristics Using Gummel Plot Technique», in 2010 International Conference on Intelligent Systems, Modelling and Simulation (ISMS), 2010, p. 396–400.</ref>
* The [[common-emitter]] current gain, <math>\beta</math>, and the [[common-base]] current gain, <math>\alpha</math>,
* {{anchor|Base ideality factor|Collector ideality factor}}Base and collector [[ideality factor]]s, <math>n</math>,
* Series [[electrical resistance|resistance]]s and [[leakage current]]s.
Sometimes the DC current gain, <math>\beta</math>, is plotted on the same figure as well.