Crest Factor

The crest factor or peak-to-average ratio (PAR) is a measurement of a waveform, calculated from the peak amplitude of the waveform divided by the RMS value of the waveform :


C = {|x|_\mathrm{peak} \over x_\mathrm{rms}}

The peak-to-average power ratio (PAPR) is a related measure that is defined as the peak amplitude squared (giving the peak power) divided by the RMS value squared (giving the average power):


\mathit{PAPR} = {{|x|_\mathrm{peak}}^2 \over {x_\mathrm{rms}}^2} = C^2

Crest factor and PAPR are therefore dimensionless quantities. While the crest factor is most simply expressed by a positive rational number, in commercial products it is also commonly stated as the ratio of two whole numbers, e.g., 2:1. The PAPR is most used in signal processing applications. As it is a power ratio, it is normally expressed in decibels (dB).

The minimum possible crest factor is 1, 1:1 or 0 dB.

Read more about Crest Factor:  Examples, Digital Multimeters, Peak-to-average Ratio (PAR) Meter, Applications

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