im having problems understanding the behavour of the hybrid parameter hre in the bjt AC model. im using the pi equivalent circuit to simulate the relation between hre and Ic (Dc value). i am not considering Rb Rex Rc or Ccs so the model is simplify to al the remaining elements
my problem is that when comparing the graphic i obtain by simulating this equivalent circuit with the datasheet graph i dont understand why there is a change in the slope of the curve. im using the 2n3904 transistor parameters, down below i post the graph i obtain by aplying the gray meyer equations for the components values and the graph of the 2n3904 datasheet
im using the values of the spice models parameters that the datsheet of the 2n3904 provides as the data for my theorical model
Anyone has any idea whats effect is causing the change in slope? i could not find any information in electronics books or searching on the web
Sorry for my bad english Cheers!