LinkSwitch-TN2 not working properly in Buck configuration
We have designed a 5V buck based on DER-507(https://ac-dc.power.com/sites/default/files/PDFFiles/der507.pdf) using LNK3206D.
But the output is 64V as opposed to 5V.
Circuit diagram attached. The HV+ and HV- is from a 120uF capacitor on a 100W TOP259 Flyback supply. We used ES1J(600V, 1A, 35ns) for both the diodes.
We have already tried swapping out LNK3206D(with that from a different vendor) and replacing 1.2mH general purpose axial inductor with 2mH Ferrite core inductor. All cases behaving in the same manner.
LED D51 not populated.
评论
Hi PratyushJayachandran,
Apology for the late reply. Please let us know just in case you have further inquiries.
Thanks and Regards,
PI-Lupin the Third
Is SC1099 equivalent to LNK3206?
My local PI representative told us that SC1099 can be used instead of this but on reading the datasheet I found that SC1099 doesn't have any reference for operation on buck mode.
Is there some other inexpensive Semi Custom part or other series that I can use for Universal to 5V, 300mA, transformer less buck convertor?
Hi PratyushJayachandran
Good Day!
For input 85Vac - 265Vac and 5Vo with 300mA load Buck topology application, LNK3206 is suited for this application. I suggest that you use the standard Power Integration part.
You can register and use the Online PIExpert to compute for the design circuit values.
https://piexpertonline.power.com/site/login
Application note for LNK TN2 is AN70.
Thanks
Regards
PI-Chloe
I have designed this buck convertor based on DER-507 for 5V.
The output voltage is close to 34V as opposed to 5V.
Circuit Diagram and PCB Attached.
| Attachment | 大小 |
|---|---|
| Auxiliary.jpg (208.85 KB) | 208.85 KB |
| Auxiliary_2.jpg (96.56 KB) | 96.56 KB |
| Auxiliary_3.jpg (95.64 KB) | 95.64 KB |
Hi PratyushJayachandran
Good Day!
Please help to provide the full requirement of the design.
Is the Vin DC or AC?
Minimum Vin
Maximum Vin
Output Voltage
Output Current
What is the value of the output inductor L11?
Please advise the manufacturer part number.
At what condition did you see the 34V output?
Thanks
Regards
PI-Chloe

Never mind, it worked.