TINA/Spice/OPA170: Spice Model having a problem with VEE

Jim Mallabar

Part Number: OPA170
Other Parts Discussed in Thread: TINA-TI,

Tool/software: TINA-TI or Spice Models

Hello,

I recently downloaded the Spice model of the OPA170 for use in an Altium CircuitStudio simulation. The model is causing the simulation to crash when VEE is processed. It does not matter if VEE is negative, 0, or positive.

I am attempting to simulate a circuit that uses rails of +14 and - 14V.

The simulation run showing two errors:

[Error]	Simulation	XSpice	Error: Unknown variable gain\xiq	8:36:25 AM	11/29/2017	28
[Error]	Simulation	XSpice	Error: Cannot evaluate device equation for g1\xiq-\xu1	8:36:25 AM	11/29/2017	29

The two errors at the end point to this model in the netlist file:

.subckt VCCS_LIM_IQ VC+ VC- IOUT+ IOUT-

.param Gain = 0.001

*.param Gain = 1e-3

G1 IOUT+ IOUT- VALUE={IF( (V(VC+,VC-)<=0),0,Gain*V(VC+,VC-) )}

.ENDS VCCS_LIM_IQ

This subcircuit is called by the top level OPA170 subcircuit twice:

XIQ+ VIMON MID VCC MID VCCS_LIM_IQ

XIQ- MID VIMON VEE MID VCCS_LIM_IQ

My XSpice skills are very rusty, I suspect there is some sort of issue with the syntax here.

Any suggestions?

Have any other users attempted to use CircuitStudio for simulation of an op amp?

over 7 years ago

0 Nikhil Gupta (Product Folder Models) over 7 years ago

TI__Mastermind 39210 points

Jim,

I would recommend trying this in TINA-TI. It is a free simulator from TI and we have a nice video training series that you can use in case you are new or unfamiliar with TINA-TI. This should take care of any incompatibility issues like the ones you might be facing.

0 Jim Mallabar over 7 years ago in reply to Nikhil Gupta (Product Folder Models)

Prodigy 100 points

That is a great theory, except:
1) I've already got the rest of my circuit in Altium. I will eventually need to simulate about 150 components.
2) The OPA170 is not in my version of Tina-TI. I'll have to update. I apparently installed in 2012.

Thanks,
Jim

0 Nikhil Gupta (Product Folder Models) over 7 years ago in reply to Jim Mallabar

TI__Mastermind 39210 points

Jim,

You do not need OPA170 to be built into the TINA-TI tool. If you go to the product folder, simply click on the TINA-TI reference design (under "Tools and Software" tab) and it should open up in TINA-TI directly. You can then copy and paste it into a new design.

Also, it would be good to upgrade to the latest version of TINA-TI as we have made significant improvements since 2012.

0 Jim Mallabar over 7 years ago in reply to Nikhil Gupta (Product Folder Models)

Prodigy 100 points

Now I see why I did not want to update by old Tina-TI package.

I cannot install the latest download. Every time I try it runs through 5 or 6 different files that "Access is Denied", all in the Tina-TI subfolder. Then the install gives up and I'm back at square 1.

I've uninstalled the old program (fail occurred before I did that as well).

I've rebooted my machine and attempted the install with no other applications running (to appease all of the IT gods).

I'm using all of the install defaults.

I've made sure there are no old Tina folders existing anywhere on my system. If the name does not start with Tina, then I am hosed.

I do not the same files failing every time, but it does always end with a Feature Transfer Error

I'm venting right now and will go find another forum if MyTi lets me.

Jim

0 Nikhil Gupta (Product Folder Models) over 7 years ago in reply to Jim Mallabar

TI__Mastermind 39210 points

Jim,

I have reached out to the developers of the tool on the installation issues. I will get back as soon as I hear back.

0 Nikhil Gupta (Product Folder Models) over 7 years ago in reply to Nikhil Gupta (Product Folder Models)

TI__Mastermind 39210 points

Hi Jim,

The developers are recommending to run the setup app in admin mode: right-click the setup and select run as admin....

They also suggest switching off the virus checker while the setup is running. It may help as well.

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TINA/Spice/OPA170: Spice Model having a problem with VEE