LMH6401: LMH6401: Simulation on LTSPICE

Sorry -  I use LTspice XVII (x64) (17.0.37.0)

BR
Wilfried

Hi Wilfried,

I typically use TINA-TI which can be downloaded for free and has dedicated component models. However, you can follow the instructions in this video to generate a .cir file to create the LMH6401 component in LTSpice. 

For you convenience, I have also attached the .cir file for the LMH6401. Please try generating the component from this .cir file.

Let me know if you have any other questions or face any other issues.

LMH6401.CIR

Thanks,

Nick

Hello Nick,
it does not solve the problem.

I have already installed TINA-TI, but this program has so many bugs that I don't want to work with TINA-TI.
(Besides LTspice has much more functionality).

Actually, by changing some SPICE parameters, I managed to make the above example work.

But this only works if the voltage source is 1kHz.
At 14MHz it doesn't work then, because there are convergence problems.

BR
Wilfried

Hi Wilfried,

I simulated the circuit that you referenced from the other E2E thread using both TINA-TI and Pspice for TI without any error using the default simulation settings. Are you running into an error simulating the roey_lmh6401.asc circuit or did you modify that circuit?

Also, because the LMH6401 is a high slew rate part, it is prone to convergence errors if it is used with a high slew rate or has complex circuitry connected. Please see the following notes to adjust simulation parameters to have convergence:

Thanks,

Nick

Hello Nick,
thank you very much for your efforts.
I believe you that you can simulate the circuit also in P-SPICE. I have TINA-TI also on the PC and there it runs without problems.
So it seems to be a problem of LTSpice. There are a lot of tips in the LTspice forum on how to solve convergence problems, but none of them worked.

Apart from the fact that TINA-TI has many bugs (e.g. it doesn't keep the settings for the diagram settings, although the checkmark is set for it), many functions can only be done with a purchase version.
I have that available in another company, but the bugs are the same.
Some have already been fixed by the manufacturer, but I
am not the testing department of DesignSoft.
So I decided to use LTSpice - I need results now and there is no time to experiment with software.

The device is only a small part of the whole circuit that is simulated.
If the IC cannot be simulated, I have to look for another one that works in LTSpice.

Thanks again for your help
BR
Wilfried

Hello Wilfried,

I appreciate your time and efforts in working with us on the model behavior.  I did find an older e2e thread with the original model author who provided a .CIR file for better convergence:

https://e2e.ti.com/support/tools/simulation-hardware-system-design-tools-group/sim-hw-system-design/f/simulation-hardware-system-design-tools-forum/632359/tina-spice-lmh6401-spice-simulation-error

I understand as engineers we cannot spend our design time debugging SPICE software or tweaking parameters without seeing benefits.  May I ask which features of the LMH6401 you are looking to evaluate in SPICE?  Perhaps we could help provide additional data or simulation results which could help address the information you wish to simulate.

If there are elements of the existing or in-progress design which are already done in LTSpice or are only available in LTSpice, please let us know.  If a particular device only has an LTSpice model, we could assist with testing your overall circuit to provide the LMH6401 simulation results you are looking to obtain.

Nick is able to assist with further simulations and has verified the LMH6401 model does work as intended in both PSPICE and TINA-TI.  If the issue is the usability of LTSpice with high-frequency amplifier models, we would like to help provide an expedited solution to your evaluation of the LMH6401.  Sharing your circuit and allowing us to help you simulate will be quicker than debugging LTSpice; the LMH6401 model works in other simulator software.  

We would be happy to help verify the LMH6401 is the device you 

Thank you for your time.

Best,

Alec