LNK6775K problem/solution
Hello everyone on the forum.
I have one problem, and it would be good if there was a solution to this.
I did a design where I use the LNK6775K and everything works fine in the 85Vac to 265Vac range.
Specifically, I have now received a request from a customer that they need to go down with an input voltage of up to 40Vac.
Is there a solution for the same chip, or do I have to change the whole design?
Thanks in advance, Aleksandar
Comments
Hi and thanks for your reply.
I don't have any information about the transformer from the manufacturer.
It was specifically designed for this chip and this schematic.
With best regards, Aleksandar.
| Attachment | Size |
|---|---|
| LN6775K.pdf | 996.65 KB |
Hi,
If you are looking for magnetics design support, use online tool on PI website.
https://ac-dc.power.com/design-support/pi-expert/pi-expert-online/
Regards
csbabu
Hi Aleksandar,
The output power and voltage was not specified. The minimum voltage required on the drain at start-up is 50V to charge the BP capacitor. You need to re-design the transformer (Lmag) and bias winding turns to deliver the required power at minimum input voltage. Please monitor thermals due to additional loss.