What is the formula to calculate the value of Rf (feedback resistor) in a summing amplifier circuit? - Quora
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![filter - Calculating Fc (cutoff) of series to RC to ground on inverting input of non-inverting amplifier - Electrical Engineering Stack Exchange filter - Calculating Fc (cutoff) of series to RC to ground on inverting input of non-inverting amplifier - Electrical Engineering Stack Exchange](https://i.stack.imgur.com/Dlo4M.png)