AlienCircuits
Member level 5
Hello,
I wrote a long explanation of what I'm doing and trying to figure out, but I'll just get the question out:
If I'm regulating a high voltage at about 800V and need to sense the output for my feedback loop and it needs to be divided down to ~1.25V (factor of .00156), how do I hope to minimize ripple to mV range when the feedback loop will probably put this signal below the noise floor (the ripple is about 20 µVpp at the feedback input)?
My spice simulation with my chosen opamp spice model seems to have no problem responding to this very low µV signal, but I am using high value resistors and I doubt this opamp will really see the µV ripple when I go to build it.
I almost think that I need to make a separate feedback path with an AC coupled feedback that only is used to eliminate ripple.
I wrote a long explanation of what I'm doing and trying to figure out, but I'll just get the question out:
If I'm regulating a high voltage at about 800V and need to sense the output for my feedback loop and it needs to be divided down to ~1.25V (factor of .00156), how do I hope to minimize ripple to mV range when the feedback loop will probably put this signal below the noise floor (the ripple is about 20 µVpp at the feedback input)?
My spice simulation with my chosen opamp spice model seems to have no problem responding to this very low µV signal, but I am using high value resistors and I doubt this opamp will really see the µV ripple when I go to build it.
I almost think that I need to make a separate feedback path with an AC coupled feedback that only is used to eliminate ripple.
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