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 is a two-port electronic circuit that uses electric power from a power su ...
is sometimes taken as the
frequency range
Spectral bands are regions of a given spectrum, having a specific range of wavelengths or frequencies. Most often, it refers to electromagnetic bands, regions of the electromagnetic spectrum.
More generally, spectral bands may also be means in ...
(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 (waves), phase of the output as a function of input frequency. The frequency response is widely used in the design and ...
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 electronic voltage amplifier with a differential input, a (usually) single-ended output, and an extremely high gain. Its name comes from its original use of performing mathem ...
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 and electromagnetics, slew rate is defined as the change of voltage or current, or any other electrical or electromagnetic quantity, per unit of time. Expressed in SI units, the unit of measurement is given as the change per seco ...
in volts per second and the peak-to-peak
voltage
Voltage, also known as (electrical) potential difference, electric pressure, or electric tension, is the difference in electric potential between two points. In a Electrostatics, static electric field, it corresponds to the Work (electrical), ...
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 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
A parameter (), generally, is any characteristic that can help in defining or classifying a particular system (meaning an event, project, object, situation, etc.). That is, a parameter is an element of a system that is useful, or critical, when ...
).
[ TDA1013B power amplifier IC specifications]
References
Audio amplifier specifications
Sound
Waves
{{acoustics-stub