10bit ADC but with SDS1104X-E features - Page 1
Forum section: electronics / testgear

author: Harjit
author_rank: Regular Contributor
timestamp: December 09, 2018, 02:08:35 am
content: About to purchase a SDS1104X-E.Was wondering if there was a similar scope but with a 10bit ADC?Plan to use it for brushless motor and optical sensor stuff for robots.Thanks,Harjit

author: Rerouter
author_rank: Super Contributor
timestamp: December 09, 2018, 04:52:08 am
content: There are, but they cost a fair bit more, e.g. R&S RTB2000So you need 10 bits of dynamic resolution? e.g. 1024 steps for a measurement, or you want to see the noise on a large dc component?

author: nctnico
author_rank: Super Contributor
timestamp: December 09, 2018, 10:39:51 am
content: I might be wrong but IIRC some of the Hameg oscilloscopes have more than 8 bit ADCs. The downside is that those oscilloscopes have a 640x480 display.

author: EEVblog
author_rank: Unknown
timestamp: December 09, 2018, 10:50:15 am
content: The RTB2004 does, but is not cheap.Owon XDS3000 have a cheaper higher bit scope.Higher bit scope are more the domain of USB scopes than benchtop scopes.

author: wraper
author_rank: Unknown
timestamp: December 09, 2018, 11:03:06 am
content: Quote from: EEVblog on December 09, 2018, 10:50:15 amBut they don't have the features Zynq provides.

author: wraper
author_rank: Unknown
timestamp: December 09, 2018, 11:12:44 am
content: Quote from: Harjit on December 09, 2018, 02:08:35 amWhy would you need 10 bit scope for that?

author: ebastler
author_rank: Super Contributor
timestamp: December 09, 2018, 11:51:01 am
content: Quote from: wraper on December 09, 2018, 11:03:06 ampascal_sweden, is that you?! Long time no see!

author: tautech
author_rank: Super Contributor
timestamp: December 09, 2018, 07:01:47 pm
content: Quote from: Harjit on December 09, 2018, 02:08:35 amQuoteFeatures, which in particular ?Dual ADC's ?Memory depth ?Decode ?500uV/div full BW sensitivity ?1 Mpts FFT ?History, Sequence, Search ?Webserver ?Bode plots ?Non reflective glass TFT display ?Pass/Fail ?400V inputs ?LAN, dual USB ?MSO option ?AWG option ?WiFi option ?etc. etc.Good luck with your hunt at this price point.Oh, and BTW, the Eres 0.5 - 3 bit mode might give you the additional resolution you seek.

author: Harjit
author_rank: Regular Contributor
timestamp: December 09, 2018, 08:15:15 pm
content: Want to be able to see noise on a large signal - basically, a decent dynamic range.From a memory depth point of view, anything more than 1M points per channel is fine.Can you elaborate on the Eres 0.5 - 3 bit feature? Is it decimating the signal to get more bits? If so, it might be enough. I haven't started using it.Thanks for the tip on the Owon. I saw Dave's video reviews and he seemed quite down on it - it was weird because he seemed upset from the get go. Anyway, he talked about a lot of user interface, thermal design and usage issues. Didn't seem there were that many functional issues - once it was configured but there were configuration (user interface)issues. From looking at the datasheet for the ADC, it can do 12bits at 1GS/s and 14 bits at 105MS/s. The closest in price seems to be the XDS3104AE. Initially, I couldn't tell how the sampling rate changed with number of channels but found it in the manual. In 8 bit mode @ 4 Ch it is 250MS/s. In 12 bit mode @ 4 Ch it is 125MS/s. In 14 bit mode @ 4 Ch it is 100MS/s. I'm quoting 4 Ch because that is the important case for me.

author: tautech
author_rank: Super Contributor
timestamp: December 10, 2018, 07:10:47 am
content: Quote from: Harjit on December 09, 2018, 08:15:15 pmOK if you can't use AC coupling then you need a good offset range.The SDS1004X-E datasheet lists the offset capabilities in the Vertical specshttps://www.siglentamerica.com/wp-content/uploads/dlm_uploads/2018/05/SDS1000X-E_DataSheet_DS0101E-E03B.pdfQuoteNothing at all demanding then.QuoteIn this excellent review, Eres is covered in some detail:https://www.eevblog.com/forum/testgear/siglent-sds1104x-e-in-depth-review/Download this from the first post that includes the Eres chapter:SDS1104X-E Review 26-50.pdf

author: nctnico
author_rank: Super Contributor
timestamp: December 10, 2018, 07:45:10 am
content: Be careful with Eres (or other high resolution modes). You'll need to have some amount of white noise in the signal to make oversampling work. And the ADCs also need to be linear. All in all Eres is nice to make a signal look cleaner but if you want extra resolution then you need the extra bits. There is a good reason there are >8bit oscilloscopes!

author: ycui7
author_rank: Contributor
timestamp: December 10, 2018, 07:46:10 am
content: Quote from: Harjit on December 09, 2018, 08:15:15 pmIn most case, you don't need 10-bit scope to see small noise on large DC components. You can turn up the gain on the input, let the trace go off screen and use the DC_Offset to bring trace back to screen. Siglent scope can do 1mV/div on top of 1V no problem. Old Tektronix analog scopes were very good at measuring this type thing.The trick is to make sure the scope won't go into phase reversal or have terrible overdrive recovery. The Siglent's overdrive recovery is not great, but if you just need to see noise on a DC signal, it is no problem. If you want to see 1mV noise on large AC signal, you will need to get a Keysight or LeCory one (only certain models, Tektronix should be OK, but I never used any of their digital ones), which has good overdrive recovery capability.A 10-bit or higher resolution scope will NOT help you, if1. they do not have digital phosphor type display (most recent ones have it)2. they have lousy analog front end. In my opinion, majority so-called high resolution data acquisition is short on analog front end design, so you won't have true 12-bit or 16-bit performance.