Products > Test Equipment
Show us your square wave
tautech:
--- 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
--- End quote ---
Could you please explain where do you get this 400ps from?
--- End quote ---
1 GHz models. ;)
JohnG:
--- 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
--- End quote ---
Could you please explain where do you get this 400ps from?
--- End quote ---
1 GHz models. ;)
--- End quote ---
Yes, thank you. I followed the link you provided and then looked up the specs for both models of the scope. I should have made this more explicit.
I am only nitpicking about the risetime because this is an important spec for my job (and for this thread). Anyone evaluating a scope has to balance their needs, budget, and the feature set of the scope, but I think there might be at least one thread about that already :).
John
RAPo:
Square wave from an HP 3300A, a rise time of 287.87ns.
tautech:
--- Quote from: JohnG on February 28, 2022, 06:29:09 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
--- End quote ---
Could you please explain where do you get this 400ps from?
--- End quote ---
1 GHz models. ;)
--- End quote ---
Yes, thank you. I followed the link you provided and then looked up the specs for both models of the scope. I should have made this more explicit.
--- End quote ---
It need be made clear the slower risetime screenshot was from a 1 GHz enhanced SDS5054X not this new 2 GHz SDS6204A and therefore is not even a true representation of SDS6104A risetime performance.
--- Quote ---I am only nitpicking about the risetime because this is an important spec for my job (and for this thread). Anyone evaluating a scope has to balance their needs, budget, and the feature set of the scope, but I think there might be at least one thread about that already :).
--- End quote ---
Sure. :)
Yet we must look at the full picture of the stated risetimes of Leo's pulsers measured with SD30 sampling heads that are specified to 40 GHz and some members here have earlier versions of Leo's pulsers that are slower 40-50ps versions.
Still looking at these fast edges can only be as reference/comparisons with scopes of the BW's of the last few posts.
2N3055:
--- 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
--- End quote ---
Could you please explain where do you get this 400ps from?
--- End quote ---
1 GHz models. ;)
--- End quote ---
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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