Gain–bandwidth product
The gain–bandwidth product (designated as GBWP, GBW, GBP, or GB) for an amplifier is a figure of merit calculated by multiplying the amplifier's bandwidth and the gain at which the bandwidth is measured.
For devices such as operational amplifiers that are designed to have a simple one-pole frequency response, the gain–bandwidth product is nearly independent of the gain at which it is measured; in such devices the gain–bandwidth product will also be equal to the unity-gain bandwidth of the amplifier (the bandwidth within which the amplifier gain is at least 1). For an amplifier in which negative feedback reduces the gain to below the open-loop gain, the gain–bandwidth product of the closed-loop amplifier will be approximately equal to that of the open-loop amplifier. "The parameter characterizing the frequency dependence of the operational amplifier gain is the finite gain–bandwidth product (GB)."