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 is then related to the slew rate in volts per second and the peak-to-peak voltage swing by

where is expressed in hertz. In data sheets for commonly available operational amplifiers, slew rate is usually given in volts per microsecond.

Specifying power bandwidth

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Power bandwidth may be specified as a frequency limit or shown in the form of a graph (e.g. as maximum available voltage swing versus frequency, often with power supply voltage as a parameter).[4]

References

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  1. ^ Audio Power Amplifier Design Handbook by Douglas Self; page 22
  2. ^ "Answers - the Most Trusted Place for Answering Life's Questions". Answers.com.
  3. ^ The sound reinforcement handbook by Gary Davis, Ralph Jones; page 197
  4. ^ "Archived copy" (PDF). Archived from the original (PDF) on 2009-12-28. Retrieved 2010-02-06.{{cite web}}: CS1 maint: archived copy as title (link) TDA1013B power amplifier IC specifications