In summary, the selection of the op-amp is important for the operation of this circuit, especially for precision instruments. For a photodiode circuit to work properly, the design must meet some basic requirements: the circuit must be stable with enough gain to present a full range to an ADC; the offset voltage must be small and not drift over temperature; the AC response must be fast but without excessive ringing; and there be an acceptable signal to noise ratio. As with other analog designs, the designer is required to make trade-offs to achieve the desired performance.