Products > Test Equipment
Show us your square wave
rf-loop:
--- Quote from: 2N3055 on February 28, 2022, 08:31:54 pm ---
--- Quote from: tautech on February 28, 2022, 05:51:41 pm ---
--- Quote from: 2N3055 on February 28, 2022, 05:41:53 pm ---
--- Quote from: JohnG on February 28, 2022, 01:13:12 pm ---
I also think it is worth pointing out that the measured data shows something closer to 400 ps and 250 ps respectively, meaning the measured risetime is more than 10% higher than the spec in both cases. One could argue that 10% is not that bad, but my prior experience has been that if proper care is taken, most scopes I have used have met or exceeded this spec.
I am curious if this is an artifact of how the scope calculates risetime, a setup problem (e.g. a thin cable), or something else. It would be informative to see the edge on a shorter timescale, say 0.5 ns/div, with cursors showing the 10% and 90% points. Then one might get a better idea of what is happening.
John
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Could you please explain where do you get this 400ps from?
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1 GHz models. ;)
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There are two basic hardware variants of SDS6000.
One has 2 ADC and maxes out at 1 GHz. It comes in 10/12 bit and is China only. That one will have 400 something ps risetime, similar to SD5104X.
Other one is 2 GHz capable platform with 4 ADC. That one is available in 10/12 bit in China only, and in 8 bit global release. Being 2 GHz capable and sampling at 5GSs/s on all channels, when run at 1 GHz it will have 350 ps risetime.
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China domestic only SDS6000 H10 Pro and H12 Pro 350MHz, 500MHz and 1GHz models have datasheet risetimes 1ns, 700ps and 450ps.
These models are different and only available in China. As @2N3055 told different platform including also fact that 2 ADC.
In these models ADC fNyquist is 1.25GHz when more than 1 channel is in use in either channel pair.
China domestic only SDS6204 H10 Pro and H12 Pro 2GHz. It have datasheet risetime 230ps. This model have separate ADC for every channel.
In this model ADC fNyquist is 2.5GHz independent of number of channels in use simultaneously.
Outside China models SDS6000A are 4 ADC models like this China domestic 2GHz model. These all Outside China models are all 8 bits without known exception.
These models are SDS6054A, 6104A and 6204A. These all are based to this 4 ADC platform as is also China domestic 2GHz model only.
These 4 ADC 500MHz, 1GHz and 2GHz models datasheet risetimes are 550ps, 350ps and 230ps.
In these all models ADC fNyquist is 2.5GHz independent of number of channels in use simultaneously.
As can be seen looking these bolded times, risetimes are not based on the 350 / BW “rule of thumb” because the BW shape is not Gaussian for compelling reasons, if one realize that this is not an entry-level hobby model.
They are just hobbyists / noobes who think the best hacking is to get more BW. Many times it is not. Without full exclusion that in some cases it may give more without high adverse effects.
For many entry-level scopes, the best hacking is to discard an over-wide BW, relative to the sampling frequency, and this must be done inside the hardware before the ADC. I have not seen these wise and not so easy modifications here in forum at all.
Martin72:
Show us your squarewave, today a lecroy WR9054 (500Mhz, 20GSa/s), Bodnar 10Mhz 40ps.
Martin72:
Same, but with my sds2k+...
tautech:
--- Quote from: Martin72 on March 05, 2022, 07:42:17 pm ---Same, but with my sds2k+...
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Any different in 10 bit mode ?
Performa01:
--- Quote from: tautech on March 05, 2022, 07:43:58 pm ---
--- Quote from: Martin72 on March 05, 2022, 07:42:17 pm ---Same, but with my sds2k+...
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Any different in 10 bit mode ?
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We would expect even a huge difference! Something more like 3 ns rise time istead of <700 ps. ;)
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