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LM25119: Can an op-amp be placed between the output and the FB pin

Part Number: LM25119

I am working on a design where I would like to be able to adjust the output of a power supply remotely.  I am thinking of using the LM25119 and placing a summing amplifier between the output of the supply and the FB pin and I would sum in a voltage to change the total output voltage.   Will the phase delay through the op-amp cause this to be an unstable solution?

I would like to be able to adjust the output voltage between 1V and 18V, with a maximum output current of 15A.  

  • Hi Mark,

    I would not recommend to place an amplifier directly between output and FB pin. This will certainly change the characteristic of the control loop. However, you can contruct a resistor divider, and use an amplifier or other circuit to adjust the resistor divider ratio to get different output votage.

    Regards,
    Weidong