Simulated Inductor

Non-Ideal InductorNon-Ideal InductorThis circuit uses a single op-amp to simulate a non-ideal inductor. The imput impedance of the circuit is

zin = ein / in = R1 + R2 + R1*R2*SC

which is the impedance of a non-ideal inductor with series resistance

  Rs = R1 + R2

and inductance

  L = R1*R2*C.

The Q of an inductor is W*L/R.  The simulated inductor has a Q of

  Q = W*R1*R2*C / (R1 + R2)

Here is the CCICAP input file that describes the simulated inductor:

.title A Simple Gyrator Circuit
.par fo 1.kHz
.opt r&i
.ac 20 10 { fo 10 / } { fo 10 X }
.calc zin { ein iin / }
.calc Q { zin IM zin RE / }
.plot ac png zin 19.k 21.k
.plot ac png zin >
.plot ac png Q
.ckt
v ein 1 1a 1.
am iin 0 1a
r r1 1 2 10.k
r r2 2 0 10.k
ioa a1 1 3 3 0
c c1 3 2 { r1 r2 + 2 PI X fo X r1 X r2 X / }
.end
.go
.stop