Keysight Technologies 3458A Guide D'utilisation page 479

Speed with Resolution
– 16 bits @ 100 kSamples/s
– 18 bits @ 50 kSamples/s
The 3458A offers you complete flexibility for speed and resolution over the audio
frequency bandwidth. The DCV measurement path can digitize your audio
frequency signal with less than 175 ns trigger latency and less than 100 ps
measurement-to-measurement jitter. Through the track-and-hold path, the
3458A can digitize repetitive signals up to 12 MHz at 50 kSamples/s with 16 bits
resolution by using sequential sampling (subsampling).
Digitizing analog signals
Most digital signal processing systems may be represented as illustrated in
Figure
In any digital processing system, there is a minimum allowable sampling rate
called the Nyquist Rate and it is specified by the Sampling Theorem, summarized
as follows:
– When digitizing an analog signal, the sampling rate must be a least twice as
Keysight 3458A User's Guide
E-1.
great as the highest frequency component (f
signal. Frequency components higher than f
frequency range below f
sampled signal. For example, since a square wave can be represented as an
infinite sum of sinusoids (Fourier Series) and contains very high frequency
components, attempting to digitize this signal without an anti-aliasing filter on
the input will severely alias the captured signal so that representations of the
actual signal may be meaningless.
High Resolution Digitizing With the 3458A
0
and interfere with the accurate representation of the
0
) in the spectrum of the sampled
0
will "alias" down into the
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