Hi, At the URL:
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there is some theory for a standard OP Amp based I/V converter. When using a capactive sensor, is it possible to cancel the low pass filter instability effect mentioned (due to Rf, Cs) by another method, instead of placing Cf across the feedback resistor? Im looking for a way of restoring stability without reducing the bandwidth or gain of the circuit. I had initially thought of some sort of current mirror buffer between the feedback resistor and the non-inverting input, so the feeback resistor is not fully presented to the sensor, and therefore the introduced low pass action is minimised.. Comments please. regards, JEFF