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EDU33212A jitter on ramp waveform and trigger out

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Anthocyanina:
not having much need for the ramp waveform until now, I had not noticed how bad the jitter was on the falling edge of a positive ramp and trigger out with this generator. I'm wondering if this is expected for a function generator, or if there may be something going on with my unit or this model in particular. the screenshots with the ramp waveform in channel one are moved half a period to the left to center the falling edge on the screen. Jitter is over 200ns peak to peak, and slightly worse for the trigger out signal at 100Khz.

I then used a sine wave to see how much worse the trigger out jitter got at higher frequencies, and something strange happens, which I'm not even sure how to describe it, but the screenshots show it. Only at 10MHz does the trigger out jitter seems to not be present, or at least not as bad as at other frequencies

What do you all think about this?
Thank you

Kleinstein:
It is normal, or at least not unusual to see quite some jitter from a digital (DDS / AWG) function genrator at most frequencies. This comes from the sampling method to genrate the signal and has natural limitations. Normally I would have expected a bit less jitter though, more like 50 ns_pp.

The sine wave looks like the reconstruction filter is not doing a good job - that looks more like a somewhat unexpected weakness.

Anthocyanina:

--- Quote from: Kleinstein on October 02, 2022, 05:19:27 pm ---It is normal, or at least not unusual to see quite some jitter from a digital (DDS / AWG) function genrator at most frequencies. This comes from the sampling method to genrate the signal and has natural limitations. Normally I would have expected a bit less jitter though, more like 50 ns_pp.

The sine wave looks like the reconstruction filter is not doing a good job - that looks more like a somewhat unexpected weakness.

--- End quote ---

Thank you, I decided to also test the ramp of the generator that comes in the oscilloscope, and got the same result, then i tried the generator from the analog discovery 2 and also got the same result, so i connected the keysight generator to the analog discovery oscilloscope, and saw that the jitter there was much less, and also on a rigol oscilloscope, which matches well enough with how it looks like on the analog discovery.

I now would like to see other people's ramps using these same settings: 4vpp into Hi Z, 100KHz, 100% symmetry, triggering on 0v rising edge and centering the falling edge on the oscilloscope, all images of this on different oscilloscope/generator combinations would be welcome.

Thank you!

Attached how it looks like on the rigol and ad2.

Someone:
The slow rising edge of the ramp is introducing jitter in the trigger position, try looking at the jitter from falling edge to falling edge (or referenced to a square sync signal).

Anthocyanina:

--- Quote from: Someone on October 02, 2022, 10:18:53 pm ---The slow rising edge of the ramp is introducing jitter in the trigger position, try looking at the jitter from falling edge to falling edge (or referenced to a square sync signal).

--- End quote ---

of course this was the reason! :palm:

same ramp, triggering on a square wave, no horrible jitter  :-[

Thank you, Someone!

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