I’m working on device modelling (specre model) of a pn junction diode. There are parameters gap1 and gap2 for bandgap voltage (Egalpha and Egbeta). Analytically, when egalpha and egbeta terms are changed, the bandgap voltage at a particular temperature changes.

Vg(T) = Vg0 - ((alpha * T^2)/(T+beta))

But I couldn't observe any difference in the performance of the diode nor the bandgap reference circuit when I simulated in cadence.
Could anyone please tell me why this would happen?

Thanks Geoffrey. I think that would be in Hspice. What about spectre models? Do you have any idea how to define levels in a spectre model?

By the way, this is all covered in the Spectre® Circuit Simulator Components and Device Models Reference manual. Take a look either via cdnshelp or looking at <SPECTREinstDir>/doc/spectremod/spectremod.pdf - there's a chapter in there in the diode equations, and it covers the different temperature level parameters too.

Regards,

Andrew.