How to rectify "Time Step is too small simulation error" in Multisim 12.0 ?

[A.D.]

Hi,

I am using Multisim 12.0 and I am trying to simulate a circuit of PWM generator using TL494 ic. The problem I am facing is that every time I run the simulation, an error occurs saying time step is too small. All the electrical connections seem to be fine. I also tried customizing the interactive simulation settings but no use. Kindly suggest a solution in this regard.

I am attaching the circuit for reference.

Thanks 

Akshay Deshpande

[Tien_P]

Hi Akshay,

The TL494 part is a custom part and the model contains syntax that is not supported by SPICE. Where did you get this model?

[A.D.]

Hi Tien_P ,

Thank you for the response. Actually, I was looking for an IC that could generate PWM and found out this TL494 part. Then I tried to simulate a sample circuitry in multisim. But TL494 part was not available. Then I found out a multisim simulated circuit using the same ic on the internet. From that circuit I added TL494 part to my user database in multisim. Thats how I got TL494. 

How can I solve the issue?

Thanks and Regards,

[Tien_P]

Hi,

Multisim is a mixed mode simulator that means it can simulate a circuit containing both SPICE and XSPICE models. However, when you create a component, you cannot combine the two types of model.

We don't have the chip you want to use available in the database, there are PWM conceptual models look in the Power group under the Power Controllers family.

[A.D.]

Thank you for the input. I will consider your suggestion.

Regards,