Problem T7
Consider the usual non
-
inverting amplifier op
-
amp circuit, shown below.
You will recall that, for an ideal op
-
amp, the circuit gain is
V
out/V
in
= 1 + (R
2
/R
1
) .
This can be arbitrarily large
, depending on your choice of resistors. Now
ass
ume that the op
-
amp has a gain of A=1.0 (instead of
infinity
) and derive
the formula for the circuit gain V
out/V
in
.
Can
V
out/V
in
still be arbitrarily large?
Hint: Golden Rule #1, which says that V
+
=V
–
, can no longer hold. Instead
V+ –
V
–
= V
out
.