Estimating the Crest Factor (Peak-to-RMS Ratio) for a Sum of Sinusoidal Signals (Download)
The crest factor, or peak-to-RMS ratio, is a signal metric to quantify the dynamic range of a signal. It provides a link between its RMS value and its peak value. Because the RMS value is often known or easily measurable, the crest factor provides a means of quickly estimating its peak value.
It’s often used when specifying an analog-to-digital converter (ADC) to avoid exceeding the range of the converter, yet still provides sufficient resolution of the signal about its RMS value. The parameter is also useful in data-recovery applications to estimate the peak-to-peak jitter from its RMS value to avert bit errors or when specifying an amplifier to avoid intermodulation distortion at signal peaks.