Capacitor network simulation

[buenos]

hi.

is there a free program, what I could use to simulate a capacitor network?
Selection of different capacitors (mixed ceramic and tantalium), multiple quantities, different values together...
I would like to simulate the result impedance over frequency, for decoupling network design for digital systems.

I found these, but not good:
switcher cad: doesnt have capacitors below half uF
programs from cap.manufacturers: those show the response of 1 capacitor at a time.
Kemet spice: can not mix ceramic with tantalium in the same diagram
Cadence Allegro PCB-PI: not free (26k$)

 

[buenos]

oh, now i can see, that the kemet spice does all needed things.


but i dont understand some things:

there are very high impedance peaks at all of the different capacitors resonant frequencies. If I simulate with Allegro PCB-PI, then these big peaks are not there. why?

I can specify extra series inductance. but when i use multiple numbers of the same type of capacitor, then the extra L is added separatelly for each, or once to all together?

how to determine mounting inductance exactly? I know what it depends on but how to get the exact value?