Plotting operating point values in DC sweep

[Svenn Are Bjerkem]

Hi,
I run a DC-sweep on the common mode input voltage on an operational
amplifier. This should cause some movement in the operating points of
the input transistors. I try to plot the value of vdsat vs. swept
vin_cm, but by using the OP("/N1" "vdsat") I only get one operating
point, the value that is saved in the opInfo in psf directory. If I look
in the dcSweep result, the only data saved for the N1 transistor is the
current through drain.

Any idea what I do wrong?

Kind regards,
--
Svenn

 

[Andrew Beckett]

Hi Svenn,

The OP function gets DC operating point data, not the results from a DC
sweep, which are separately stored.

What you'd need to do is create an include file, with:

save N1

or

save N1:vdsat

in, and then use the results browser to access this information. Off the top
of my head, you can probably get this via pv("/N1" "vdsat" ?result "dcSweep")
or something like that... but it's probably easier to look in the results
browser.

The save statement tells it to save this info for all analyses run.

Andrew.

On Thu, 18 Nov 2004 16:41:49 +0100, Svenn Are Bjerkem <svenn.are@bjerkem.de>
wrote:

Hi,
I run a DC-sweep on the common mode input voltage on an operational
amplifier. This should cause some movement in the operating points of
the input transistors. I try to plot the value of vdsat vs. swept
vin_cm, but by using the OP("/N1" "vdsat") I only get one operating
point, the value that is saved in the opInfo in psf directory. If I look
in the dcSweep result, the only data saved for the N1 transistor is the
current through drain.

Any idea what I do wrong?

Kind regards,