Transresistance Amplifier – Definition and Equivalent Circuit:

In transresistance amplifiers the input signal is current and the output signal is voltage. The ideal transresistance amplifier provides an output voltage in proportion to the signal current, and the proportionality constant is independent of the magnitudes of R_s and R_L.

From the equivalent circuit of a transresistance amplifier shown in Fig. 19.5, we find that if R_in << R_s then I_in ≈ I_s and if R_out << R_L, then

and

An ideal transresistance amplifier should have zero input and output resistances.