Innoswitch3- EP family IC blasting problem in power supply

Hello venkateshwaran,

Good day and thank you for using Power Integrations product as part of your design.

For me to better understand the situation, I would really appreciate it if you could clarify the following points.

1. What is the input voltage specification of the design?
2. At what input voltage and output current are you observing this pulse bunching?
3. Are you using one of our reference design boards or did you make your own prototype?
4. Did you use the PI Expert Online tool when designing the power supply?
   1. If the answer is yes, please provide the PI Expert file so we can review it further.
   2. If not, did you use any reference design examples from our website (power.com)? Please provide the link.
5. What do you mean by "some boards only the IC blasted"? Can you provide an image of the blasted IC?

Kindly provide the schematic diagram, PCB layout (Gerber files preferred), transformer file from the manufacturer (with primary inductance and number of turns of each winding), and the PI Expert file of the design (if there is one) so we can review further and identify what may be causing the issue.

Thank you and I look forward to your response.

Regards,

Tommy

Hello Tommy

Thanks for the reply.

1. Input voltage specification is 180VAC - 280VAC
2. At 280VAC input voltage and 3.5A output current we are getting this pulse bunching.
3. We made our own prototype 
4. Yes, we have used PI Expert for designing

5. kindly share the mail id to share the design files, Gerber and other confidential documents. 

   Regards,

   Venkatesh

Hi venkateshwaran,

Since the documents are confidential, we can do an offline communication through our PowerPros Online Support. Kindly submit a request through this link: PowerPros Online Support | Power Integrations and explain in detail the issue you're currently encountering. Please also attach the requested files (zip file) and images in the request so the team can review it thoroughly and give feedback on what might be the cause of the issue. Rest assured that the team will get back to you as soon as possible once your request is logged in the system.

Thank you and have a great day.

Regards,

Tommy