Electronic – Operational Amplifier gain bandwidth product


If the gain bandwidth product of an operational amplifier is a constant and |Vout/Vin| is also a constant does that mean that the operational amplifier will not function for all but 1 frequency? Please explain.

Best Answer

Open loop Vout / Vin isn't constant - it rolls off with frequency and obeys the gain-bandwidth product approximation: -

enter image description here

What you may be being confused with is the DC open loop gain and, from the diagram above that would be quoted in a data sheet as 1 million.