## EE 212 Lab

### Prelab 11: Operational Amplifiers - Part III (Negative-Impedance
Converters and General Impedance Converters

1. Analyze the circuit in figure 1 of the lab to show that it is a negative
impedance converter, i.e., show that Z_{in } = V_{in}/I_{in}
= -Z.

^{}

^{}

^{}

^{}

^{}

^{}

^{}

^{} ^{}

2. What is the time constant, τ, for the circuit of figure 4 in the lab?

3. Analyze the circuit of figure 2 in the
lab to show that its input impedance is Z_{in}=Z_{1}Z_{3}Z_{5}/(Z_{2}Z_{4}).
Verify that if Z_{2} or Z_{4} is a capacitor and
the other impedances are resistors, then Z_{in }is the impedance
of an inductor.