eldo_user

Specifying Simulation Output
Extract Examples
.step param p1 1 10 0.5
.extract tran label=idsm1 yval(ids(m1), 50n)
.extract sweep label=idsm1_min min(extract(idsm1))
.extract sweep label=p1_idsm1_min
+ xycond(xaxis, extract(idsm1)==extract(idsm1_min))
The first extract command finds the value idsm1 for each step. The second extract command
finds the minimum of idsm1 over the sweep. The third extract command finds the p1 value
corresponding to idsm1_min.
Related Topics
Extracting Information
Extract Examples
Example Combining Sweep Extract and .ALTER
This example shows how the sweep extract also works on waveforms generated from an
.EXTRACT combined with a .ALTER.
The example is based on the loop_stability_opamp.cir netlist in $MGC_AMS_HOME/
examples/eldo/, with some changes to the inputs, extracts, and with the addition of a .ALTER
block.
VINP INP 0 AC 1 0
VINN INN 0 AC 1 0
...
.ac dec 10 1 1e8
.plot ac v(out)
.extract ac label=G400M yval(vdb(out),1k)
.alter DM_GAIN
VINP INP 0 AC 0.5 90
VINN INN 0 AC 0.5 -90
.extract sweep label=CMRR yval(meas(G400M),1)-yval(meas(G400M),0)
The first extract command, labeled G400M, finds the y-axis value of the waveform vdb(out) at
1kHz. The .ALTER block, DM_GAIN, replaces the opamp input voltage sources with a
differential input where VINP is shifted in phase from VINN and extracts the G400M
information again. The .EXTRACT SWEEP command in the .ALTER block finds the
difference between the two extracted y-axis values to generate the CMRR result (ratio of the
differential mode gain and common mode gain).
Extract
Alter index0 G400M
Alter index1 G400M
CMRR
Value
-1.4292E+01
6.5083E+01
7.9375E+01
Eldo® User's Manual, 15.3 333