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LNK364GN design can not reach 200mA output

Posted by: zxjsuzhou on

i'm using lnk364gn to design a power supply with 43v, and 12V@ max 200ma output,
when i was testing it , i found this design is not stable, test result is like this:

if i replace lnk364gn chip with a new one, sometimes, it works. sometimes not (it means restart again and again).
if i replace the transformer with a new one, sometimes it works, sometimes not.(it means restart again and again)

it is quite strange, i don't know why.

could you please help to check what the problems could be?

attached picture is the schematic of power supply.

thanks in advance!

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Comments

Submitted by zxjsuzhou on 01/04/2015

one interesting thing:
if i heat the chip to around 40 degree, it can startup successfully( with 12v@2000ma Load).

any suggestion?

Submitted by PI-KSAN on 01/07/2015

Thanks for posting your question into forum and we appreciate your time and patience.
As per your comment, the output power specification of your power supply is 11W (43V + 12V and 0.2 A Current).
As per the data sheet, LNK364G the maximum power it can provide is 9W 230 Vin for open frame. We recommed you to download PI Expert and PIXl's, enter your specifications, it will redesign your power supply and Transformer as per your specification.
Thanks,
PI-KSAN

sorry, it is my mistake, output power of this design is 43v@20ma, 12V@200ma, so , total power is 3.26W, i can not understand why this design is not stable, if you tell me your mail address,i can sent specification of transformer to you, my mail address is : 279934333@qq.com

thanks

 

Submitted by PI-Sarek on 05/22/2015

Hi,

I recommend that you first verify your design using our design tool which is called PIExpert.

If wfater verifying the design with the results of PIExpert, you still continue to face the issue, then please send us the PIExpert file and the transformer documentation  and we will be happy to review. You can upload the design files to the forum.

Best Regards,

PI-Sarek