The power bandwidth of an
amplifier
An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal (a time-varying voltage or current). It may increase the power significantly, or its main effect may be to boost the v ...
is sometimes taken as the
frequency range
A frequency band is an interval in the frequency domain, delimited by a lower frequency and an upper frequency. The term may refer to a radio band or an interval of some other spectrum.
The frequency range of a system is the range over which i ...
(or, rarely, the upper frequency limit) for which the rated power output of an amplifier can be maintained (without excessive distortion) to at least ''half'' of the full rated power. (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
In signal processing and electronics, the frequency response of a system is the quantitative measure of the magnitude and phase of the output as a function of input frequency. The frequency response is widely used in the design and analysis of sy ...
curves, where it refers to -3dB points in the frequency response of a band-pass filter.
Data sheets for
operational amplifiers
An operational amplifier (often op amp or opamp) is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output. In this configuration, an op amp produces an output potential (relative to c ...
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 electronics, slew rate is defined as the change of voltage or current, or any other electrical quantity, per unit of time. Expressed in SI units, the unit of measurement is volts/second or amperes/second, but is usually expressed in terms of m ...
in volts per micro second and the
voltage
Voltage, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to m ...
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
Power bandwidth may be specified as a frequency range or as a graph.
[ TDA1013B power amplifier IC specifications]
References
Audio amplifier specifications
Sound
Waves
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