What is the gain-bandwidth of an operational amplifier?
The maximum frequency for a filter circuit using that type of amplifier
The frequency at which the open-loop gain of the amplifier equals one✓Correct answer
The gain of the amplifier at a filter’s cutoff frequency
The frequency at which the amplifier’s offset voltage is zero
Explanation
In an op-amp whose open-loop response is set by a single dominant pole the gain falls at a constant −20 dB per decade all the way down to unity gain, so the product of gain and bandwidth stays constant. That constant equals the frequency at which the open-loop gain has fallen to one, and it sets the maximum bandwidth available at any given closed-loop gain.