Custom Independent Current Sources

Hello everyone,

I apologize in advance in case the question has already been answered

in a previous post (nonetheless, I would much appreciate a "pointer" to

the corresponding thread). Anyway, here's the problem:

I am relatively new (4 months) to Virtuoso (version 6.1.5-64b), ADE and Spectre and I would like to

custom-define and double-check with Spectre some independent current sources, namely by

using e.g. "iexp", "isin", or "ipulse" "ipwl" "ipwlf" etc, and perform an AC analysis with Spectre.

In particular it would be helpful to add e.g. simple current sources with the following behaviour in Laplace domain:

I(s)=A/(1+s*tau)

where "A" and "tau" are known.

Which is the best way to do it  by using the aforementioned sources?

Is there an easy way to achieve it with e.g. "iexp" or "isin" by setting the

corresponding damping factor (from e.g. tau=RC for the corresponding -1/tau pole)

and A (from the DC Current) directly inside the source? Are there any

step-by-step tutorials/guides? Do you recommend a different approach?

I tried by plugging both values e.g. in "isin", setting a "starting" frequency,

an arbitrary value for AC_magnitude (which should be "modulated" by

the damping factor) in the source panel, launching ADE and setting AC for a

target bandwidth, running Spectre, ... but I'm not getting the correct shape.

Some help panels are unfortunately not completely helpful, since they

mostly provide the same information stated in their corresponding

Property Panels for the (analog_lib) symbols, without further details.

Any help would be greatly appreciated

Best,

Stefano