The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Simulators >> AMS Simulators >> ams simulator vs psectre simulator for ams simulation
https://designers-guide.org/forum/YaBB.pl?num=1492517241

Message started by AMS_ei on Apr 18^th, 2017, 5:07am

Title: ams simulator vs psectre simulator for ams simulation
Post by AMS_ei on Apr 18^th, 2017, 5:07am

Hi,

Could anyone please explain me how different it is if a design is being run with

a) using Spectre only (using .scs file) and b) using AMS-spectre simulator (using .vams file) for a transient analysis?

which one is more advantageous and useful for ams simulation?

Thank you.

Kind regards.

Title: Re: ams simulator vs spectre simulator for ams simulation
Post by Andrew Beckett on Apr 21^st, 2017, 1:51pm

Well, the main benefit of using AMS is if you have some digital behaviour in there somewhere - then you can take advantage of the event-driven engine in AMS to improve performance. If everything is at transistor level (or you just have verilog-a models) there is no benefit in using AMS as the simulator - you have a bit more overhead and it costs you more in terms of licenses. In other words, if everything is analog, using a circuit simulator is probably a better choice...

Title: Re: ams simulator vs psectre simulator for ams simulation
Post by Ken Kundert on Apr 21^st, 2017, 8:04pm

Some people wonder if AMS Designer is less accurate than Spectre. It is not. AMS Designer employs Spectre underneath, so you can expect similar behavior and accuracy.

If you system is entirely analog, then Andrew is right, using Spectre is generally best. It is a cheaper license, and you get a much wider palette of analysis choices (AMS Designer is largely constrained to transient analysis).

However, if you are simulating a mixed-signal system, it is generally much easier to write mixed-signal models in Verilog-AMS, and they can run much faster.

-Ken

Title: Re: ams simulator vs spectre simulator for ams simulation
Post by AMS_ei on Apr 21^st, 2017, 8:32pm

Hi,

Thank you, Andrew and Ken for your valuable inputs.
I have one doubt here.
If I run stand alone Spectre on any analog design, it generates the netlist in .scs format and then run on it.

If I run AMS simulator on any analog design, it generates netlist in .vams format and then run on it.

Did you mean that running a simulation on .vams netlist (AMS simulator) and on .scs netlist (for standalone spectre) will give the same results in accuracy?

Thank you.

Kind regards.

Title: Re: ams simulator vs psectre simulator for ams simulation
Post by Ken Kundert on Apr 23^rd, 2017, 1:45pm

Of course. It is the same information, just in a different format.

-Ken

Title: Re: ams simulator vs spectre simulator for ams simulation
Post by AMS_ei on Apr 25^th, 2017, 8:49am

Thank you, Ken for your valuable inputs.

Kind regards.