Re: AC analysis

> I want to do an ac analysis to a single-ended opamp.
> I'm having some difficulty to decide how to do the test bench's and if
> I should add a vsin signal to the circuit. How should I specify the
> input signal?

It doesn't matter which type of source you are using, as they all have AC
parameters available. 
Rather choose it according to the signal shape you want during transient
simulation.

For AC, the simplest setting is to just set the AC magnitude to 1.

See 'spectre -h vsource' for a list of parameters (I'm assuming you're
using spectre).

> Furthermore, Can anyone tell me what's "Y element"?

I guess it depends... could be an element with the shape of a Y. Or an
element modeled with 
Y-parameters (http://en.wikipedia.org/wiki/Admittance_parameters).



Stéphane