Hi,
I like the versatility of the SG3525A PWM circuit. Plans are to use the PWM control in a project. I've downloaded four different SG3525 LTSPICE models, but all failed to run after installing the .sub and .asy components of the LTSPICE models.

I want a 10kHz output, possibly my circuit connections are incorrect. Can anyone in the Forum make a suggestion or post a model and circuit that outputs PWM at 10kHz using the SG3525A?

Attached are my working files.

Thanks,
Neko

 

Can anyone in the Forum make a suggestion or post a model and circuit that outputs PWM at 10kHz using the SG3525A?

Here's a basic circuit to get you started :

 

Here's a basic circuit to get you started :
View attachment 214608

Hi Alec_t,
Thanks for your response and circuit post. Your circuit as posted, does not run and also appears to be a different model than what I posted.

Thoughts?
Thanks,
Neko

 

The sim works fine for me. Did you give the sim enough run time to allow for the slow-start feature?
You said you have four spice models. Try those. If none work in my posted circuit, say so and I'll post my model.

 

The sim works fine for me. Did you give the sim enough run time to allow for the slow-start feature?
You said you have four spice models. Try those. If none work in my posted circuit, say so and I'll post my model.

Well, there's good news and bad news. Good news is that one of the models I downloaded worked with your posted circuit. The bad news is that maximum duty-cycle for the chip is 50%. I should have checked the datasheet sooner.
Thanks again,
Neko