Power bandwidth

The power bandwidth of an amplifier is sometimes taken as the frequency range (or, rarely, the upper frequency limit) for which the rated power output[1] of an amplifier can be maintained (without excessive distortion) to at least half of the full rated power.[2][3] (Some specifications may mandate 100% of the rated power; sometimes referring to the full-power bandwidth.)

It should not be confused with "half-power" bandwidth, only used in conjunction with filter frequency response curves, where it refers to -3dB points in the frequency response of a band-pass filter.

Data sheets for operational amplifiers often use the term (full-)power bandwidth to indicate the highest frequency at which the achievable peak-to-peak output voltage swing is still equal to the DC output voltage range. This is also sometimes described as the slew-rate-limited bandwidth. The full-power bandwidth ${\displaystyle BW}$ is then related to the slew rate ${\displaystyle SR}$ in volts per microsecond and the peak-to-peak voltage swing ${\displaystyle V_{amp}}$ by

${\displaystyle BW={\frac {SR}{\pi ~V_{amp}}}}$

where ${\displaystyle BW}$ is expressed in hertz. In data sheets for commonly available operational amplifiers, slew rate is usually given in volts per microsecond.