Acquisition Control 12Keysight InfiniiVision 2000 X-Series Oscilloscopes User's Guide 159So, in practice, an oscilloscope's sample rate should be four or more times itsbandwidth: f S = 4f BW . This way, there is less aliasing, and aliased frequencycomponents have a greater amount of attenuation.See Also Evaluating Oscilloscope Sample Rates vs. Sampling Fidelity: How to Make theMost Accurate Digital Measurements, Keysight Application Note 1587(http://literature.cdn.keysight.com/litweb/pdf/5989-5732EN.pdf)Oscilloscope Rise TimeClosely related to an oscilloscope's bandwidth specification is its rise timespecification. Oscilloscopes with a Gaussian-type frequency response have anapproximate rise time of 0.35/f BW based on a 10% to 90% criterion.An oscilloscope's rise time is not the fastest edge speed that the oscilloscope canaccurately measure. It is the fastest edge speed the oscilloscope can possiblyproduce.Figure 23 Sample Rate and Oscilloscope Band widthLimiting oscilloscope bandwidth (f BW) to 1/4 the sample rate (fS /4)reduces frequency components above the Nyquist frequency (f N ).f Sf Nf S/4-3dBAttenuationAliased frequencycomponentsFrequency0dB
