On inductor simulation using a unity-gain amplifier

The authors deal with two recently reported active circuits for realization of a grounded inductor using a single unity-gain amplifier and RC networks. It is shown that the inductance parameters are very sensitive to amplifier gain; this can be remedied by using a high-gain differential-input operational amplifier. Amplifier imperfection in respect of nonzero output impedance is found to make both circuits behave similarly. Sensitivity of tuned circuits using the active inductances is analyzed and conditions for minimum sensitivity are derived.