LTC4125: How to suppress the rise of FB terminal voltage after Optimum Power Search

Hi Dachin, 

The high FB rise is normal and it is designed to be like that so it is easy for LTC4125 to hit the exit condition of the optimum power search. However, if you would like to lower the FB rise, you can reduce the rated voltage for the zener diode (D4, on page 14 of the DC2330A demo manual) in the presence detect circuit. 

Thanks,

Wenwei. 

Hi Wenwei

I understand that the rise in FB voltage is the correct operation. I evaluate the change in FB voltage when the rated voltage of the Zener diode(D4) is changed.

Thank you.

Dachin.

Hi Wenwei

I understand that the rise in FB voltage is the correct operation. I evaluate the change in FB voltage when the rated voltage of the Zener diode(D4) is changed.

Thank you.

Dachin.