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yet another op-amp bias question

  • Thread starter Anthony Fremont
  • Start date

Anthony Fremont

Jan 1, 1970
I posted a schematic over in ABSE along with a question. The jist of it is
that I have a sallen key high pass filter (inverting) designed by FilterPro
and I need to have the output biased at 1/2Vcc. The input is DC blocked by
capacitors so no joy there. There is a resistor from the + input to ground
and I don't want to mess up its function in the filter design, but I need to
apply a bias voltage there so that the input doesn't get clipped.


Jan 1, 1970
Without seeing your schematic - here's a blind suggestion. If the
value of the resistor to ground on the + input is critical to the
transfer function, you can simply replace it with a voltage divider
which: 1) sets the DC value you want, and 2) whose parallel combination
gives the value of the original resistor.