There is a pulse width jitter caused by some kind of aliasing between various unsynchronized events. My screen capture grabs only one frame of video, but you can see it in the red persistence trace, and I can see it on my Tek scope. I discovered this while running one of the script examples, and then confirmed that it exists in all the pulse modes of the Wavegen except as follows:
It is here with these "simple" settings:
It is here with these "basic" settings:
For my buffer setting and 1% at 5KHz the pulse width here varies from 1.870 us to 1.98 us. It should be 2 us of course. The actual frequency is similarly unstable by a few Hz around 5KHz. Synchronization with a "Run" argument of 200 us or less cures the problem. It appears that when this is =< the set period, it dominates as the period of the waveform. :
Placing Wavegen into "autosynchronized" mode does the same thing, but enforces a 200 us "run" argument:
As expected, the "run" argument automatically takes on the period of the set frequency. However, note that at 2KHz a glitch appears in the pulse. (It is real):
None of these setting produces a waveform that matches the settings exactly. The glitch is particularly troubling. Am I doing something wrong here?
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P. Fiery
Hello,
There is a pulse width jitter caused by some kind of aliasing between various unsynchronized events. My screen capture grabs only one frame of video, but you can see it in the red persistence trace, and I can see it on my Tek scope. I discovered this while running one of the script examples, and then confirmed that it exists in all the pulse modes of the Wavegen except as follows:
It is here with these "simple" settings:
It is here with these "basic" settings:
For my buffer setting and 1% at 5KHz the pulse width here varies from 1.870 us to 1.98 us. It should be 2 us of course. The actual frequency is similarly unstable by a few Hz around 5KHz. Synchronization with a "Run" argument of 200 us or less cures the problem. It appears that when this is =< the set period, it dominates as the period of the waveform. :
Placing Wavegen into "autosynchronized" mode does the same thing, but enforces a 200 us "run" argument:
As expected, the "run" argument automatically takes on the period of the set frequency. However, note that at 2KHz a glitch appears in the pulse. (It is real):
None of these setting produces a waveform that matches the settings exactly. The glitch is particularly troubling. Am I doing something wrong here?
- Paul Vo
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