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LM5575: About buck switching regulator LM5575MH/NOPB

Part Number: LM5575

Hi Support Team,

My customer has the question as follows:

I am confirming the action in case of IC and peripheral component failure.

Could you tell me the action in the following status.

Input voltage is 46V, output voltage is 24V, FB resistor(which set the output voltage level)the above one is 18.7kΩ and the below one is 1kΩ

①When the above one of FB resistor is open, what is the output voltage?(how many volts?)
   When the above one of FB resistor is short, what is the output voltage?(how many volts?)
②When the below one of FB resistor is open, what is the output voltage?(how many volts?)
   When the below one of FB resistor is short, what is the output voltage?(how many volts?)
③When FB pin is open, what is the output voltage?(how many volts?)
④When it is short between FB pin and GND, what is the output voltage?(how many volts?)

Thanks so much.

Best regards,
Yuki

  • Hi Yuki,

    ①When the above one of FB resistor is open, what is the output voltage?(how many volts?)-----close to Vin
       When the above one of FB resistor is short, what is the output voltage?(how many volts?)-------equal to Vfb=1.225V
    ②When the below one of FB resistor is open, what is the output voltage?(how many volts?)-------equal to Vfb=1.225V
       When the below one of FB resistor is short, what is the output voltage?(how many volts?)---------close to Vin
    ③When FB pin is open, what is the output voltage?(how many volts?) ---------close to Vin
    ④When it is short between FB pin and GND, what is the output voltage?(how many volts?)--------close to Vin

    B R

    Andy