TINA/Spice/OPA376: OPA376 Transient Analysis with Tina-TI

Ming Liao

Part Number: OPA376
Other Parts Discussed in Thread: TINA-TI,

Tool/software: TINA-TI or Spice Models

Hi,

By doing Transient Analysis with "OPA376_sboc261d.tsc" for 3 input voltage sources of Sine, Triangular & Square waves in Tina-TI, the simulated waveforms are as attached. However, there is big distortion on the output waveforms (marked in red circles) if the input sources are Triangular & Square waves. Would you please check why?

Thanks.

Ming

over 7 years ago

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

TI__Mastermind 39210 points

Ming,

You could try to constrain the max step size.

Go to Analysis >> Set Analysis Parameters >> Change "TR maximum time step" to say 100n or so.

0 John Miller - Sensing over 7 years ago

TI__Mastermind 40295 points

Ming,

I suspect the distortions are due to a transient simulation time steps that are too big.
The default max step size can be seen in the table at Analysis/Set Analysis Parameters.
The default setting for the TR Maximum Time Step is "10G" which is an adaptable step size that changes from step-to-step.

The distortion disappears if the "10G" is changed to a smaller fixed max time step, like 1 micro-second (1u).
Please give this a try and let me know if you still see the problem.

Regards,
John

0 Ming Liao over 7 years ago in reply to John Miller - Sensing

Intellectual 450 points

Hi John,
It looks not helpful to set TR Maximum Time Step to 1000G or even 1000T, but it looks OK to just set TR truncation error factor to 1 from 8.
Thanks for showing me the way of where to change the parameters.
Ming

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TINA/Spice/OPA376: OPA376 Transient Analysis with Tina-TI