TOP267EG

maybe have you a document with all the formules? like that i can develop my own solution with input range (230-400vac).

Thanks for Posting your question into forum. Yes Please go through our TopSwitch Application Note document below, you can find the design calculations :
http://ac-dc.power.com/zh-hant/design-support/product-documents/applica…
Please go through it and let us know if that's helpful for your design calculations.

Thanks,
PI-KSAN

sorry but i don't see all the formule in your document :/

I can't develop my own solution without that because i have an input range too high (230-400vac).

i can't develop my own solution with PI Expert.

I can develop the transformer with my input range with PI Xls but i can't calculate all the components

This family uses a 725V FET. The DC voltage from rectified 400Vac will be 560Vdc, which does not leave enough margin for a normal flyback pulse of approx 150-200V, which is why it is only rated up to 300Vac.

As pointed out in your post, with a 400VAC input, the rectified bus voltage can be as high as 560V and this puts a limitation on the ability to design with a parts rated for 725V though this can be done.

Another approach is to use an arrangement called the StackFET which comprises of a Power Integrations integrated switcher IC such as the Tiny Switch or the TOPSwitch and stack a MOSFET on top of it. This then enables design with very high input voltage.

You can find several examples of this on our website. you can also Google search for DER-105 from Power Integrations.

We do not have an application note specifically for the StackFET though the design rules are fairly similar.

There are several application notes on PI website that provide detailed equations if you wish to do your own designs. You may also find information about design consultants who can help you to design with our parts by contacting one of our sales offices in your area.

https://www.power.com/sites/default/files/product-docs/an32.pdf

Thanks and regards

Dear sir,
I am using TOP267EG IC in my project.And i have generate the schematic using PI Expert tool. But when making on the circuit in output it showing 48v and it is causing damage to the IC. I have attach the schematic of circuit. so sir please look in to and tell me why it is causing damage to IC. And i have tested in 3 circuit and all the 3 time causing damage to ic.

Hi Vishal,

Thanks for your inquiry.
Did you change anything from what was generated by the PI Expert design tool? Can you send me the PIExpert file and the actual transformer construction?
At what condition is this happening (Vin and load current)? If you add a load, will the output voltage drop? If you did not modify anything, you may start your investigation with the transformer and the feedback loop.

Regards,
PI-Picard

I have attach the document of pi expert. we keep all the things same and only change the optoisolator LTV-816S-TA1.first we check the output with no load and we have see the output 48v. and then we have connect 20mA load and it was decreasing little bit that is 45v.but in both time it damaged the chip.
Then we taken out the optoisolator outside and simply apply the control pin of top267 5.8v and 4mA current but then also it damage the chip.so please provide me the solution.

Hi Vishal,
So your output is 27V and not 48V? If your output is not 27V and not 48V then you should not be putting some load in the unit since it is already abnormal from the start. Kindly recheck all your component if it is still in good condition especially for TL431 since usual rating is below 48V. Then double check the winding orientation of the transformer. The IC topology is sensitive to TRF orientation since you mentioned output will decrease when you load it up.

Regards.