HELP WITH CHOOSING THE CORRECT SPICE SIMULATOR

[Mystogan]

Hello everyone,

I am basically trying to design an ADC in a transistor level. The option at hand is to use LTSpice. But when i start simulating more than some 40 transistors it is taking forever to simulate. I just wish to know if there are any spice simulators (FREE of cost) available in the internet which can work fast for simulating some medium scale of 100-200 transistors.

Hoping an immediate reply..

 

[kubeek]

edit: wrong thread

 

[eTech]

Hello everyone,

I am basically trying to design an ADC in a transistor level. The option at hand is to use LTSpice. But when i start simulating more than some 40 transistors it is taking forever to simulate. I just wish to know if there are any spice simulators (FREE of cost) available in the internet which can work fast for simulating some medium scale of 100-200 transistors.

Hoping an immediate reply..

hi

Why do you want to simulate at the transistor level?

Or do you really want to simulate its behavior?

eT

 

[Mystogan]

hi

Why do you want to simulate at the transistor level?

Or do you really want to simulate its behavior?

eT

Thanks for the reply!
I want to do it as a part of my (VLSI course) college project.
Things worked well as long as i simulated individual blocks(<some 20 mosfet), but when i integrated them to work together its taking a lot of time.
I have a full design in my mind, hopefully it will work. But no.of transistors that can be simulated turns out to be a bottle neck(presently using LTSpice).
I would appreciate if you could let me know about spice simulators(free is preferred) which satisfy my needs.

 

[cowboybob]

It's not the SIM package that is your problem, it's the processing speed of your computer.

Large, multi-component circuits such as you describe, using any particular SIM software (especially the free ones), chew up enormous processing power since they are, literally, mathematically calculating the individual responses of each and every component at every iteration.

They don't call it VLSI for no reason.

 

[MikeMl]

LTSpice is coded to run multi-threaded on up to 4 cores.

The bottleneck is not the underlying Spice sim engine; it is the FET models you are using.

 

[cowboybob]

LTSpice is coded to run multi-threaded on up to 4 cores.

The bottleneck is not the underlying Spice sim engine; it is the FET models you are using.

Mike has a point.

See also: http://www.simonbramble.co.uk/lt_spice/ltspice_lt_spice_tutorial_6.htm

Although, you may still see sim function degradation depending on your PC's processor's configuration and clock speed.

 

[Mystogan]

Yes,Now i got it. You both are right, Mr.CowboyBob & Mr.Mike. I tried the simulation on a different computer and it worked like a charm.
Thanks guys...