The bandwidth of an operational amplifier (op amp) circuit is determined by the gain-bandwidth product (GBP) of the op amp, which is the product of the open-loop gain and the frequency at which the gain drops to 1.
Assuming that the op amp has an ideal gain of infinity (i.e., the open-loop gain is much larger than any closed-loop gain), the GBP is equal to the unity-gain bandwidth of the op amp, which is the frequency at which the gain drops to 1 when the feedback is set to unity gain.
Therefore, if the op amp has a gain-bandwidth of 220 kHz, the bandwidth of the whole amplifier circuit will depend on the closed-loop gain of the circuit.
For a non-inverting amplifier, the closed-loop gain is given by:
A = 1 + (Rf/Rin)
where Rf is the feedback resistance and Rin is the input resistance.
The bandwidth of the circuit can be approximated as:
Bandwidth = GBP / A
Assuming a typical non-inverting amplifier with Rf = 10 kΩ and Rin = 1 kΩ, the closed-loop gain would be:
A = 1 + (10 kΩ / 1 kΩ) = 11
Substituting the values into the formula for bandwidth, we get:
Bandwidth = 220 kHz / 11 = 20 kHz
Therefore, the bandwidth of the whole amplifier circuit would be approximately 20 kHz in this case.