RO of bipolar transistor while simulating in Hspice

[tomandrosea]

ro of bipolar transistor

I use hspice to simulate a op-amp . The out file show 2 two transistor with
same Ic and VA have different ro .,one 's ro is almost 2 times another's .That is why ?
Regards !

 

[Davood Amerion]

ro of bipolar transistor

put 2 op-amp schematic to evaluate.

 

[darkk]

ro of bipolar transistor

If you really setup everything the same for 2 op-amp, my rough guess is that the hspice model is much more complicated than the one you see from textbook, ie., it might involve some other parameters. But the order of magnitude of variation is not small.