hi...i've spice digital models that i use in Cadence Orcad for digital circuits. i want to move to ADS. i used the generic FET model in ADS and manually filled in the spice parameters but the simulation results are off by .3-.5 V, which is significant here, and also the temperature simulations are off (circuits in Orcad and ADS don't work over the same temperature range).
is this discrepency a common thing when moving spice models to ADS? i expected very similar results...difference only in 10e-2 range. the real reason to move the models to ADS is to use DAC, goals and optimizer to extract better spice model using measured data so that digital simulations in Orcad are better.
also is there an automatic way of importing spice models from Orcad to ADS and vice versa. right now i'm doing it manually. thanks a lot.
is this discrepency a common thing when moving spice models to ADS? i expected very similar results...difference only in 10e-2 range. the real reason to move the models to ADS is to use DAC, goals and optimizer to extract better spice model using measured data so that digital simulations in Orcad are better.
also is there an automatic way of importing spice models from Orcad to ADS and vice versa. right now i'm doing it manually. thanks a lot.
From there you can specify to import a Netlist file, and then you can specify which flavor of SPICE to import to ADS. You can either import to ADS components or to an ADS netlist that can be included with a netlist include element in your simulation.
As for going back to spice once you've brought something into ADS and modified it, I don't know that is possible directly in the ADS GUI. One thing, though, is when you simulate, you can always see the netlist.log file, and it is pretty straight forward to convert that with an external script or something.
About the simulation discrepancy...Check closely on the default values for model parameters that aren't set explicitely. I have had experience in the past where those default values have led to discrepancies between the simulators. Just something to check...
Only works with HSPICE files syntax. For all other types (like PSPICE), you will still need to use File > Import from ADS Main window.
Only works in 2008 Early Access as this was a new feature introduced. Will not help you if you have 2006A and its update releases.
In general, if you have trouble matching your results with another simulator, its best to contact Technical Support directly. The forums are not a good place to get answers to time critical issues.
Nilesh