I sweep temperature from -40 to 80 and find that the voltage range of bandgap output is about 2mv .
but when I do tran simulation at the same time sweep temperature from -40 to 80 ,the result is that the voltage range of bandgap output is about 20mv.
why the result of dc simulation is different with tran simulation?
the current of collector is 5uA.
What kind of simulation environment are you using?
I was suspecting that the dc simulation computes an operating point and uses some linearized model in the temperature sweep, while the transient simulation might calculate a dc operating point for every transient step, and that the difference would be coming from that. Is such a thing possible with your current setup?