TNY27X input voltage below 85 VAC
Posted by: leonardo.mavi
on
Hello,
I'm designing a flyback regulator using a TNY27x with an input VAC as low as 45 V. Datasheet refers to input VAC range as "85-265 VAC" and table on page 16 states a minimum drain supply voltage of 50V, but I can't find the exact minimum input voltage.
What if I remove the R5 undervoltage resistor and my VAC drops below 85V? Are there any derating characteristics available?
Thanks,
Leonardo Guidi
Comments
Hi Leonardo,
You can design your flyback below 85Vac as long as the DC voltage across Drain Pin is not below 50V.
Removing R5 will disable undervoltage feature which is better for your design since you want a very low input voltage (45VAC).
Regards,
Jedidiah
我测试85V的时候欠压保护了，自动重启，怎么回事？
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