PsPspice detected an imported model containing transistors or diodes after editing breakout.lib.

Hi Michael,

Including non-TI transistor/diode models will trigger the soft landing that restricts the tool to 3 markers. You can still run the simulations, but will be limited in how many nodes you can monitor.

Not sure what's going on with the Noise sim. Let me check into that.

Likewise with removing the model changes. Seems like that should've canceled the soft landing.

I might need your zipped test bench to confirm all this, but let me see what I can find out first.

David

Hi Michael,

I'm not familiar with the noise analysis video 16-1.

Can you share that link?

I need your Project/Design so that I can see what's going on from my end. Otherwise, I'll just be guessing.

David

Hi David,

The PSpice for TI training Lab is downloaded from Cadence - https://www.pspice.com/pspice-for-ti/training-course

I did a fresh install on another machine where I could trigger/remove the TI soft landing by modifying the QbreakN model in Qbreakout.lib. I copied the breakout.lib and breakout.libsig to my first PSpice install and got that working as well.

When I trigger the TI soft landing (and have to put 1-3 markers on the schematic), the noise simulation output variables do no appear in the add traces window.

The following 2N2222 model were used for QbreakN:

+IS=3.88184e-14 BF=929.846 NF=1.10496 VAF=16.5003
+IKF=0.019539 ISE=1.0168e-11 NE=1.94752 BR=48.4545
+NR=1.07004 VAR=40.538 IKR=0.19539 ISC=1.0168e-11
+NC=4 RB=0.1 IRB=0.1 RBM=0.1
+RE=0.0001 RC=0.426673 XTB=0.1 XTI=1
+EG=1.05 CJE=2.23677e-11 VJE=0.582701 MJE=0.63466
+TF=4.06711e-10 XTF=3.92912 VTF=17712.6 ITF=0.4334
+CJC=2.23943e-11 VJC=0.576146 MJC=0.632796 XCJC=1
+FC=0.170253 CJS=0 VJS=0.75 MJS=0.5
+TR=1e-07 PTF=0 KF=0 AF=1

Example project is attached in zip 

Noise_example.zip

Hi Michael,

Thanks for pointing me to the training material. I had searched ti.com and pspice.com's training but didn't download this thinking it was just a repetition of other training. 

I'm glad that you've got it working. It was confusing that when you went back to the original unmodified model it was still in soft landing.

Looks like you resolved that.

I'll check with Cadence on why the noise analysis is disabled during soft landing. It might be that the noise analysis requires monitoring many nodes that would violate the soft landing criteria. Alternatively, it's likely that some advanced features are disabled in soft landing to provide incentive to upgrade to the full version. If you are likely to be a heavy user of PSpice, then upgrading is probably the solution that you'll want.

Light or occasional users will be fine with PSpice for TI.

I'll play around with the project your supplied, but I don't think there's anything wrong. Just how soft landing and noise analysis interact.

David

Not sure why the tutorial says to monitor the bias circuit instead of the output. That's odd.

I'm not sure what you mean.

Bias for the Q1/Q2 current mirror is set by RBIAS.
V1 is source and differential output is out1/out2.

I don't quite understand how this works.

With added markers appearing in the output plot, the noise output variable tick box is still greyed out in the "Add Trace" dialog box. The output window shows the "AC (and Noise) Analysis" ran.

When not in soft landing it is not necessary to add any markers to run "AC (and Noise) Analysis" and plot all noise variables.

This is how it looks in soft landing:

Hi Michael,

This is a bit of a black box. I'll ask for a clearer explanation and post that here if possible (unless it is proprietary).

David