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ADP1047 current sense resistor question

Question asked by kevin.hsu on Oct 3, 2013
Latest reply on Oct 9, 2013 by kevin.hsu

current.jpg

Attached the pix as below . I had a question about 10Kohm !!

 

Should it 10kohm ? I do some testing about this value , so far if the resistor smaller during THD testing will better .

Do you have any comment for the 10k resistor design ?

 

Second question , it about VAC pin . We design a 1000W based on ADP1047 , During Brownout testing , In full load condition if "Vin on" and "UV Fault" is too close will get some risk . It like due to full load condition , input current is very big so the input voltage will drop in the ac line .

When we trum down the input voltage until trigger the UV fault , So the system will shuntdown (Output = no load , input current will getting small) , The input voltage no drop and getting higher . It means when brownout to in the VAC will error due to the ac line voltage drop and system will turn on ~ off ~ on ~ off until the system shuntdown and needs use pson to restart it .

 

We very concern this operation , Does any advise to us ???

vin.jpg

 

Thanks so much ~

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