MSO5000 Bode Plot Capability: Is it Good Enough? [Many tips about a 1st scope]

[balnazzar]

The Micsig is way faster/easier to use, I don't regret the loss of a few "checkbox" features at all.

Tell me one thing: when you connect the Micsig with the hdmi, does it still do just 800x600? Thanks.

[Fungus]

Edit: as has been written before: in the lower end there will be comprises to be made; there is no perfect scope that does all.

It would not be difficult to make such a machine.

They don't do it because they want to be able to sell mid and high end machines, too.

[tautech]

Just be sure you've checked out the input limitations of an AD2 .....hardly anything like the 400V rated inputs on the X-E.
Instead investment in a SAG2021I for $165 will get you up and running with Bode plots immediately as no licensing is required unless you use the FG capability.

[Fungus]

The Micsig is way faster/easier to use, I don't regret the loss of a few "checkbox" features at all.

Tell me one thing: when you connect the Micsig with the hdmi, does it still do just 800x600? Thanks.

Yes.

[nctnico]

Just be sure you've checked out the input limitations of an AD2 .....hardly anything like the 400V rated inputs on the X-E.

Doesn't matter when the AD2 is used for bode plotting and logic analysis only. The AD2 is not pretending to be a universal oscilloscope but rather more like a specialised high resolution data acquisition tool. I don't have one but it has several features that can be very handy in some situations.

[tautech]

Some SDS1104X-E screenshots of the webserver from 1 of the 24" monitors on my PC for balnazzar to consider.

We can view in 3 modes and the blue X at bottom right takes the scope display to full screen whereas the blue bar top right of the display pops out or hides the virtual scope controls. PC display must be no greater that 100% scaling to fit both the display and controls within the width of the PC display.
In webserver mode you have both local and remote control of the scope.

PC Esc button exits full screen mode.

BTW, just viewing these now posted, they are filling ~2/3rd of the width on my monitor whereas they were screenshotted full width.

[2N3055]

The Micsig is way faster/easier to use, I don't regret the loss of a few "checkbox" features at all.

Tell me one thing: when you connect the Micsig with the hdmi, does it still do just 800x600? Thanks.

None of the embedded scopes will change resolution when outside monitor is connected.

[balnazzar]

Just be sure you've checked out the input limitations of an AD2 .....hardly anything like the 400V rated inputs on the X-E.
Instead investment in a SAG2021I for $165 will get you up and running with Bode plots immediately as no licensing is required unless you use the FG capability.

Mh, it's actually a good price. Apart from its 1.5-3V limit and slightly lower sampling rate, what are its limitations with respect, say, a SDG1000X? Thanks.

[tautech]

Just be sure you've checked out the input limitations of an AD2 .....hardly anything like the 400V rated inputs on the X-E.
Instead investment in a SAG2021I for $165 will get you up and running with Bode plots immediately as no licensing is required unless you use the FG capability.

Mh, it's actually a good price. Apart from its 1.5-3V limit and slightly lower sampling rate, what are its limitations with respect, say, a SDG1000X? Thanks.

Datasheet time !

SAG1021I>P13. These have the benefit of an isolated output, ie. not referenced to mains earth.
https://www.siglenteu.com//wp-content/uploads/dlm_uploads/2021/08/SDS1000X-E_DataSheet_EN04D.pdf

SDG1000X
https://www.siglenteu.com//wp-content/uploads/dlm_uploads/2022/06/SDG1000X_DataSheet_DS0201X_E01I.pdf

[2N3055]

Re: The AD2.

Just to be 100% clear: The AD2 is NOT a great oscilloscope, it will never replace a bench oscilloscope.

What it IS is a general purpose electronics tool, it does all sorts of clever/useful things.

It might help to think of it as a "Swiss Army Knife" - they're not the greatest knife in the world but they have all sorts of other tools like screwdrivers and scissors and saws.

Check out all the modules here:

https://digilent.com/shop/software/digilent-waveforms/

Edit: It looks like they forgot the curve tracer...

What is actual performance of it performing stability analysis on a switcher PSU? Dynamic range and complete amplitude range? How well it performs in presence of noise?
I searched and found no real performance figures in real world scenarios ..what is real performance of AD2?

That's completely the wrong way to think about the AD2.

I know it has Bode plot functionality but despite it's nominal 14bit resolution, it has only 2 measurement ranges.

Yep. 5V and 20V ranges.

If you're doing Bode Plots at 100mV (or above) then it'll work just fine.

(maybe even at 50mV).

And maybe not.
Like I said, you don't know. You don't own AD2 and have no knowledge or experience with measurement of Bode plots with it.  Your body of knowledge on this topic is "maybe" same as mine. And it is a 400 € device you recommend.

In an article I linked there were problems found with measurements on AD2. Basically, they wanted to use it for serious measurement and found that some of implemented measurements were a bit simplistic and not stable and reliable at higher frequencies. I have no idea if that is fixed or not but that made me think.

Plenty people are recommending AD2 but there is no real performance verification anywhere to be found.
As I don't own AD2 I asked for real data from someone who owns it or link to some real performance verification.
I'm not saying it is bad, I'm saying we don't know...

And yes, only 5V and 20V voltage range is a serious limitation. If you use it with 10x probes it becomes 50V and 200V range.
When you are trying to measure loop stability, voltages are sometimes minuscule (very small). Whole regulation loop is fighting to set error voltage to zero... That is why good sensitivity and best possible ADC is needed.

On Micisg: statistics on measurements is a basic thing. And I miss it all the time on the Micsig and am completely baffled why they didn't make it... Yes I do own STO1104C..

[egonotto]

Hello,

the SDS1104X-E  has only a Display Resolution of 800×480.

But I think it is a great scope.

The Analog Discovery and Analog Discovery 2 are small laboratories much more than a scope. They are practical in combination with breadboards. I am biased and I like them, but in the meantime they have become very expensive. Maybe you'll get them academically.

I have an Analog Discovery an Analog Discovery 2 and a Digital Discovery. If 2N3055 or someone else wants to have something tested I try it if my place (20 cm * 40 cm) is enough.

Best regards
egonotto

[balnazzar]

Plenty people are recommending AD2 but there is no real performance verification anywhere to be found.

I'm investigating. For example: https://hackaday.com/2018/06/20/analog-discovery-2-as-a-vector-network-analyzer/

Is the Discover 2’s NA mode useful? Yes. Is it perfect? No. The interconnect issue gets more and more problematic the higher you go in frequency. If you already have one of these, by all means, use the NA, especially for lower frequency work. But if you really need an NA, this probably isn’t going to be your first choice.

Also, from: https://www.allaboutcircuits.com/technical-articles/tool-review-analog-discovery-2-by-digilent/

The AD2 also includes a spectrum analyzer and a network analyzer with Bode plot capabilities. Each of these tools can be used for analysis up to 10MHz and are available for each oscilloscope channel input.

Only 10 MHz. I previously thought it got up to 30...

Also, reviewing the AD2's scope in general, from: https://www.allaboutcircuits.com/news/analog-discovery-2-vs-other-pc-based-oscilloscopes-is-ad2-worth-the-hype/

Hence, while the ADC might support a high sampling rate, we might lose some details of the input signal simply because of the lack of memory.

It just has 16K memory depth.

From various Reddit posts (AskElectronics):

1. I used an AD2 last quarter in my microprocessor system design class as an oscilloscope, logic analyzer, and frequency generator. It can do other things but I mainly used those.
It worked well but I much rather prefer a regular oscilloscope as it can be difficult to analyze fast signals. But it's a great bang for your buck. Think of it as a swiss army knife. A ton of neat tools in a small package, but all the tools are meh. Usable but meh at best.\

2. I love my AD2. It’s a Swiss Army knife of tools and fits in my backpack. I’ve used it to gather data for the last couple papers I published. It’s scope and logic analyzer has some features that do not come on your basic scopes (at least not without several upgrade tiers). It definitely has limitations with resolution, but will be fine for most non performance critical things. It is also scriptable with its own language or through a python or matlab friendly api.

A video review (may be useful for future reader of this thread):
The software seems to be indeed very good, far better than the software that comes with bench scopes, even top brand (although I just seen Siglent's and Keysight's at the university).

The NA is reviewed starting from here: https://youtu.be/0nFFJT1oV34?t=287, but it doesn't say much, apart from platitudes.

[balnazzar]

I have an Analog Discovery an Analog Discovery 2 and a Digital Discovery. If 2N3055 or someone else wants to have something tested I try it if my place (20 cm * 40 cm) is enough.

Thanks, man. 

Could you please check the limits of the Network Analyzer? Does it really gets to 10 MHz and not more (or less)?

Also, can you confirm that the software is complete, functional, and overall better than the sw that comes generally with bench scopes?

[2N3055]

Hello,

the SDS1104X-E  has only a Display Resolution of 800×480.

But I think it is a great scope.

The Analog Discovery and Analog Discovery 2 are small laboratories much more than a scope. They are practical in combination with breadboards. I am biased and I like them, but in the meantime they have become very expensive. Maybe you'll get them academically.

I have an Analog Discovery an Analog Discovery 2 and a Digital Discovery. If 2N3055 or someone else wants to have something tested I try it if my place (20 cm * 40 cm) is enough.

Best regards
egonotto

Thank you, you are very kind.
In the light of these discussions, I would like to know how well it would fare doing classic stability analysys, on a simple opamp circuit or a simple PSU.  Siglent has A.N. : https://www.siglenteu.com/application-note/power-supply-loop-response-bodeii/ where simple PSU is measured. Something like that.
Regards,
Sinisa

[2N3055]

I have an Analog Discovery an Analog Discovery 2 and a Digital Discovery. If 2N3055 or someone else wants to have something tested I try it if my place (20 cm * 40 cm) is enough.

Thanks, man. 

Could you please check the limits of the Network Analyzer? Does it really gets to 10 MHz and not more (or less)?

Also, can you confirm that the software is complete, functional, and overall better than the sw that comes generally with bench scopes?

Limit will be 10 MHz because that is the limit of internal waveform generator. Scope bandwidth is better, up to 30 MHz.

You can download software for free and use it with audio card in PC. In fact, you can try Bode plot with it if you make out breakout cables for audio card. Of course within audio range and with limited drive..

[balnazzar]

Limit will be 10 MHz because that is the limit of internal waveform generator. Scope bandwidth is better, up to 30 MHz.

So, if I stimulate the circuit with an external WG, the AD2 will bodeplot its response? Thanks.

[Frex]

Hello,

the SDS1104X-E  has only a Display Resolution of 800×480.

But I think it is a great scope.

The Analog Discovery and Analog Discovery 2 are small laboratories much more than a scope. They are practical in combination with breadboards. I am biased and I like them, but in the meantime they have become very expensive. Maybe you'll get them academically.

I have an Analog Discovery an Analog Discovery 2 and a Digital Discovery. If 2N3055 or someone else wants to have something tested I try it if my place (20 cm * 40 cm) is enough.

Best regards
egonotto

Thank you, you are very kind.
In the light of these discussions, I would like to know how well it would fare doing classic stability analysys, on a simple opamp circuit or a simple PSU.  Siglent has A.N. : https://www.siglenteu.com/application-note/power-supply-loop-response-bodeii/ where simple PSU is measured. Something like that.
Regards,
Sinisa

Hello,

I own the AD1 for many years now, and even if i have many other equipments
it was very conveniant to use in many situations. Clearly the big difference with others
PC based intruments is the software side.
It seem designed and thinked by/with real hardware engineers (not a progammer).

To answer you, yes you can perform good gain/phase responses of  closed loop gain of SMPS
with it (and measure phase et gain margin). I used it for this some month ago for
a small DC/DC converter (5W push pull) and for a 1800W 1kV/24V PSU.
I both case it worked very well after setting well all parameters.
An exemple of result below, with the corresponding step response also made with AD1.
My 2 cents.
Regards.

Frex

[Fungus]

You don't own AD2...

Ummm....

[Fungus]

Also, can you confirm that the software is complete, functional, and overall better than the sw that comes generally with bench scopes?

As I said earlier, you can download and try the software for free.

[Fungus]

Dave also did a video on the AD1:



AFAIK the only real difference between the AD1 and AD2 is the on-board programmable power supplies.

(and a prettier case)

[egonotto]

Hello,

I tried a Bode plot with an LC oscillating circuit. The signal is severely disturbed, but it still worked to some extent. Enclosed the circuit (drawn with the mouse) and the Bode plot, the signals measured with the AD2 and a signal measured with the RTA4000.

Waveforms can now run the function generator with 25 MHz, but there is a warning. This means that the network analyzer now goes up to 25 MHz.

Best regards
egonotto

[Fungus]

FWIW: Here's a screenshot taken with my AD2 with nothing connected to the input. 5 or 10 mV is about as low as it usefully goes.

Below it is a heatmap view. Note that you can have different, simultaneous views of the input signal.



AD2 specs are here: https://digilent.com/reference/test-and-measurement/analog-discovery-2/specifications

[2N3055]

Limit will be 10 MHz because that is the limit of internal waveform generator. Scope bandwidth is better, up to 30 MHz.

So, if I stimulate the circuit with an external WG, the AD2 will bodeplot its response? Thanks.

No, Bode plot and impedance analysis works by controlling generator and scope in synchronization.  AD2 has internal AWG and uses that one...No support for external AWG.

[egonotto]

Hello,

here is a 25 MHz sine with 1Vpp generated by the AD2.


Best regards
egonotto

[2N3055]

You don't own AD2...

Ummm....

OK I was wrong on that. I stand corrected.
That is excellent news..
Why are you then repeating stuff from marketing pamphlets instead showing us how well it works?
In Siglent's A.N. I linked there is very simple PSU made from common components. It is easy to replicate. Instead of expensive transformer, you can use largest common mode choke you can find and use that one. It'll work well enough.
And then run analysis and show us results, please.
I'm really curious to see how well it works. If it works well (or at least decent) it is a good news. It will also be directly applicable to OP question and comparisons to SDS1104X-E mentioned here..