Confusing DSO & AWG specifications  - Page 1
Forum section: electronics / testgear

author: mawyatt
author_rank: Super Contributor
timestamp: July 23, 2020, 05:49:37 pm
content: Hello,I've been reading the many threads and posts regarding Digital Scopes and AWG. There's so much information (and misleading information) it's hard to sift thru all this, thus this request mainly from those folks directly involved with this equipment. User experiences and GUI preferences welcome.Many scopes claim 12 and 14 bit resolution, but don't seem to identify an actual 12 or 14 bit ADC. Keysight (DSOX-1204) indicates the 12 bits is achieved by oversampling, are the other scopes using oversampling, R&S RDS2000 has 10bit ADC? What is the noise floor and dynamic range when doing FFT's in regular and oversampled modes?Scopes with built-in AWGs, what is the resolution and accuracy of the outputs. Can they support true arbitrary waveforms, can these be created from the scope or is a computer necessary (is Mac supported)? Can one capture a waveform from the scope and "easily" transfer the waveform to the AWG for replaying? What are the chip sets utilized for the DDS and DAC?Can scopes operate with external AWGs to do "easily" create Bode plots and capture and recreate waveforms? Are the external AWG capable of having waveforms "easily" created on screen, or do they require an external computer (is Mac supported). What chip sets are used for DDS and DAC.Without prior bias or knowledge my interpretation from the many threads has lead me to believe that Rigol scopes and AWGs aren't as refined as Siglent, which aren't as refined as Keysight or R&S.The usage is for a home lab, with interest more in precision than ultimate speed. The ability to have quality easily utilized Bode plots and FFT's is desirable, and easily working with external AWGs. Very comfortable with most lab equipment.Like many my budget is limited so the dedicated Keysight AWG have been bypassed which leaves the Rigol, Siglent and others for consideration. For the scope Keysight and Siglent, seem like a better choice than Rigol or another.Sorry for all the questions, but hopefully this will help other folks also.Forgot to mention also looking at programmable power supply, dual output of 30V min. at 2 amps minimum. Here the Keysight is too expensive and the Siglent (SPD3303 series) seems better than Rigol, but haven't looked much beyond this.Many thanks in advance.Best,

author: cliffyk
author_rank: Frequent Contributor
timestamp: July 23, 2020, 10:24:14 pm
content: I do not know if both the VellemanPCSU1000andPCGU100are still in production, however when paired using Velleman'sPClab2000software they can produce wonderful audio frequency to 2 MHz bode plots.I am not a big fan of PC based instruments, nonetheless the seamless manner in which these two have been merged in Velleman's software is a big exception to that "rule". Generator output and scope input are automatically scaled as needed to meet the DUT's response. THe 10 Hz to 30kHz audio frequency plotting range setting (added at my request i will add, their support is great) is a bit oddly hidden withing the toolbar drop-down menu system, but it is there.Highly recommended if you can still get them and your interests lie in the 10 Hz to 2MHz frequencies. The 'sope's software based FFT functions work well also.response of a Pyle PP555 phono pre-amo:the PCSU1000:PCGU1000:Frequency response of a Tascam DR-03 handheld digital recorder:Note the 1 dB/div scale; -0.4 dB @ 20 Hz, then essentially flat to 20 kHz, this is a pretty impressive little sucka'

author: tautech
author_rank: Super Contributor
timestamp: July 23, 2020, 11:03:05 pm
content: Whole lotta questions and all of them good.Few DSO's offer better than a native 8 bit resolution although most have ERES or HiRes modes of normally 3 bits or more. The SDS2000X Plus range might interest you where it has a 10 bit mode (100 MHz BW limited) and then ERES can also be applied on top of that.DSO's with inbuilt AWG's all suffer from limited output amplitude capability and generally their ARB capabilities are somewhat less than a standalone ARB. Most inbuilts work at TTL logic levels and have limited current capability which may or may not be a problem for some requirements.Yet they do offer better compactness if you have limited space yet most only max out to 25 MHz.Personally I'd always have a 2ch standalone unit rather than suffer the limitations of an inbuilt ARB.Capturing and transferring waveforms to an AWG.Those I play with allow for 2 methods, USB stick transfer or via the free EasyWaveX SW (Windows)where if both scope and AWG are USB or LAN connected the waveform files can be transferred with a click of a mouse.I guess there is no reason why it couldn't be run in a VM on a MAC.Bode Plot (FRA) capability has developed some since early versions and I believe that applies to most brands as they polish the functionality. Siglent has reworked theirs for the little X-E DSO's and member rf-loop looks at its capabilities here:https://www.eevblog.com/forum/testgear/siglent-sds1x04x-e-bodeplot-ii-(sfra)-features-and-testing-(coming)/I haven't played much with it since it was first released when I did this basic example:https://www.eevblog.com/forum/testgear/siglent-sds1204x-e-released-for-domestic-markets-in-china/msg1435854/#msg1435854It's somewhat improved since then.Siglent DSO's with Bode plot capability all interface seamlessly with Siglent AWG's via USB or LAN connectivity where the DSO takes charge of the AWG for the Bode plot stimulus sweeps.For a PSU I'd recommend the SPD3303X-E primarily for its nice display and the info it provides as default.

author: mawyatt
author_rank: Super Contributor
timestamp: July 24, 2020, 02:21:57 pm
content: Thanks for the replys.I've found the R&S RTB2004 uses a custom developed 10bit 1.25GSPS ADC and a TI 500MSPS 16bit DAC for the in-scope AWG. Here's an excellent review and teardown.Will add additional equipment information later.Best,