I am currently trying to build a photodiode transimpedance amplifier based on the ADA4627-1 opamp. The first result I have obtained on a prototype circuit are quite bad, as I get a lot of excess noise generated inside the circuit.
I think that the abnormal behavior of my circuit may come from the tolerance on the opamp GBW Product. The datasheet specify a GBWP of 19 MHz, with a minimum guaranteed value of 16 Mhz. As I have designed the circuit using the 19 MHz GBWP value, my hypothesis is that I have a real opamp that is slower, with a real GBWP between 16 MHz and 19 MHz.
Now I would like to test that in Spice by simply changing the value of the GBWP product of the ADA4627-1 macromodel. However, I have no idea about how to do that, and the ADA4627.cir file don't help me, since the GBWP parameter is not explicitly specified.
So, here is my question: how to change the GBW product of the ADA4627 macromodel ?
Thank you very much for any help.