Technical data

Oscilloscope Familiarization Labs 2
4000 X-Series Oscilloscopes Advanced Training Guide 25
16 Select the Clock with Infrequent Glitch signal and press the Output softkey to
turn it on.
17 Set channel- 1’s V/div setting to 500 mV/div.
18 Set channel- 1’s offset to approximately 1.00 V in order to center the
waveform on- screen.
19 Push the trigger level knob to set the trigger level at approximately 50%.
20 Set the timebase to 20.0 µs/div. At this timebase setting there will be
many cycles of the clock signal on- screen, which is typically required
when performing a precision FFT math function.
21 Press the [Math] front panel key; then press the Operator softkey.
22 Select the FFT math function. Select the softkey Span and set to
100 MHz; then set Center to 50 MHz.
You should now see a display similar to Figure 12. The scope is now
displaying both a time domain waveform (Voltage versus Time) as well as
a frequency domain waveform (Power in units of dB versus Frequency).
An FFT math function breaks signals down into their individual sine wave
frequency components. All electrical signals, including digital signals, are
composed of multiple sine waves of different frequencies. An ideal clock
Figure 12 Performing an FFT math function on a repetitive digital clock.