This tiny capacitor stabilizes the transimpedance amplifier by compensating for the input capacitance of the sensor plus op-amp. TIAs are conceptually simple: a feedback resistor (RF) across an operational amplifier (op amp) converts the current (I) to a voltage (VOUT). We begin by defining what a transimpedance amplifier is. For context, let's take a look at an example circuit. The standard equation you'll see in nearly every datasheet is: You feed a small sensor current I IN into the inverting input of an op-amp, place a feedback resistor R F from output to input.