Gummel–Poon model

It was first described in an article published by Hermann Gummel and H. C. Poon at Bell Labs in 1970.

[1] The Gummel–Poon model and modern variants of it are widely used in popular circuit simulators such as SPICE.

A significant effect that the Gummel–Poon model accounts for is the variation of the transistor

values with the direct current level.

[1] Spice Gummel–Poon model parameters[2]