Siglent SDS1104X-E and SDS1204X-E Mixed Signal Oscilloscopes

[bullonwheels]

I got one too. How do we hack ?

[tautech]

I got one too. How do we hack ?

It starts at Reply #785 but this is only for BW.
Please study subsequent posts.

[rf-loop]

Things did get weird when I turned on all 4 channels and had a 280mhz signal into channel 1, it really didn't like that, bad voltage readings, and frequency measurement, but, thats probably not unexpected.

This is expected.

--------------

?

generally:

With 500MSa/s Nyquist-Shannon "wall" is 250MHz.  All frequency components in signal what are over this Nyquist freq and what go to ADC they produce aliases. This is basic fundamental.
If there is very tight "brick wall" type filter in analog front end what stops all freq components over bit under Nyquist freq then we have not this problem.


500MSa/s : Just input 350MHz and you see 150MHz then 450MHz sinewave in and you can see nice 50MHz sinewave and then again same 50MHz with 550MHz input. (500MHz happen next folding)

If someone want see it in practice as trial with basic fundamentals lesson in school and what happen in frequency domain, just turn FFT on and then slowly adjust input signal frequency over fNyquist freq and then slowly up to over 2fNyg for seeing folding back and so on... after then can see that math (theory)  and practice is equal.

(if someone play with these (also with genuine 1104X-E) it need note that do not overdrive analog front end. Your display show attenuated level but your input signal is still what it is and  may overdrive analog front end and if you now try adjust V/div for more sensitivity for get waveform more vertical height. This may overdrive front end some parts and may generate really "miracles" to screen. Example, if signal level is -5dBm and example starting with 10MHz, perhaps vertical adjustment is 50mV/div. If signal from source to oscilloscope stay around constant then when you go to higher frequencies and you see signal level drops in scope display, due to attenuation inside scope... if now try adjust V/div for more sensitivity keep in mind that it may overdrive front end amplifiers even if you see low level in scope display. This higher level from generator is still there in analog front end circuits and this overdrive, if and when it happen,  may look really fun and weird.

"Know your equipment" (and some basics about your signal under tests)  is important rule for avoid several traps what may be even total mess instead of good measurements.

As told previously, when I get sooner or more like later, some more time I will do some tests and look around about signal sampling aliasing because so many peoples looks like falls to this trap.

But also note to manufacturers. Take better care about designing good analog filters to front end!
This is shame that  front end is such as a forgotten child. Why. And not only in bottom price scopes. Is it so that digital design is like childrens playing, just 1 and 0 but... analog DC - RF front end need real study, desing and lot of tests and developments work.  And still Siglent is not bad at all. BUt it can do better and it can do better without needing be higher price. Only it need higher skills to design and after then run circles and laugh around competitors..

[innkeeper]

Thanks RF-Loop.

I knew there would be a wall with the sampling rate though never sat down to learn the effects of it or mathematically where I would it hit it. it makes a lot of sense the way you explained it. It was my immediate reaction when i saw it behave that way that i was past the ability of the ADC to sample the input correctly as I did know with all the channels on, that the sampling rate would be 500MSa/s so it was a pretty easy conclusion to think it was some aliasing issue.

but its good to understand exactly how it behaves and why.  Thanks for the explanation.

I'm sure this won't be the last trap i hit  

I just started playing with the FFT function and comparing it to my DSA and spectrum analyzer, seeing what it takes to get it to do what i want. I'll have to run the experiment you suggested, and watch its behavior while i am playing. I am sure it will act exactly as you described.

The more I play with this thing, the more I wonder why I didn't go this way much sooner...Don't get me wrong, is not going to replace the dedicated equipment, but, I can see the need to turn those on going way down, what a huge time saver. .. i'm starting to feel a bit like rip van winkle lol. 

[rf-loop]

Here some tests with SDS1104X-E

Of course all tests are with single individual scope and without any kind of hardware modifications. Hardware is just out from factory box. Only difference is explained in this thread Reply #785

In all test image pairs both have exactly same signal source and signal pathway to scope input BNC. All scope settings equal (these settings which have some effect in this context)

I will reserve some next msg for further test results so that they stay together. This is because I show them delayed.



Picture 1.
This is made using 500MSa/s (250MHz fNyquist).
Input: Sweep from 5MHz to 250MHz, generator (HP8642B) output level 4dBm
Note 100MHz model BW shape near 250MHz, reason unknown...
 ETA:  For clarify this image. It seems that I have forget important information from image (it was all clear when there was just talking about mod, but if later some people look it out from original context it may look strange.
This Image 1. top half is SDS1204X-E (SDS1104X-E mod)
Bottom half is original SDS1104X-E "out from box".





Picture 1.1
"fold back" aliases due to input over 250MHz fNyquist but under 2fNyquist
This is made using 500MSa/s (250MHz fNyquist).
Input: Sweep from 250MHz to 500MHz, generator (HP8642B) output level 4dBm
Note: FFT 0-250MHz show now input signal alias. Remember that now when sweep freguency goes up, signal in FFT display goes down. Example input 251MHz alias is  249MHz in FFT and 499MHz frequency input alias is now 1MHz in FFT. Middle point 125MHz is from 375MHz input. Just reverse (fold back from 250MHz fNyquist)  Think you mirror horizontally this image 1.1 after picture 1. and both together is as sweep from 5MHz - 500MHz.  (image 1 start from 5MHz due to reasons with HP8642B)

--Note1 for mod 200 with 1GSa/s this BW shape (think FFT horizontally mirrored and 250 - 500MHz. Of course just same as in FFT also normal scope time domain show this alias.
--Note2 for original 100MHz model with 1GSa/s, this is very different and it continue nearly same  attenuation from 250 to 500MHz
--Note3 for both scope screen in image 1.1. Trigger event freq counter (right top corner) show Alias frequency. Of course because this scope have full digital side trigger system and of course it trig to alias -  it can not know it is alias instead of direct true input signal. I have removed counter display because during sweep it is always late and it might cause confusion.


Picture 1.2
Here is combination of some FFT - Sweeps using SDS1104X-E Original.
From previous images you can self look and think same kind of combine with SDS1104X-E (mod200)
Note specially original 100MHz BW shape when samplerate is 500MSa/s. It is near same as (mod200) exept this dip what have 250MHz center. But, 1GSa/s is very different (because.... and so on... all know that if example 100MHz signal in digital side is alias from 400MHz (if 500MSa/s) input or just original 100MHz input signal - digital side can not know it at all. This need also know when use scope what have example some strongly advertised user adjustable DSP filters what may in some cases produce total mess what nice looking product brochure do not tell you. Of course normal user know these potential traps due to education and experience and knows how to identify a potential problem situation and knows how to avoid problems)




Picture 1.3
This is SDS1104X-E mod200
This image can compare with picture 1.2 about SDS1104X-E original.
With 1GSa/s FFT is useable up to 500MHz but of course user need understand and know signal attenuation and front end limits.
Note that FFT noise floor is far down out from screen bottom. Because 5dB div scale and here interested signal top (BW shape)



Picture 1.4
SDS1104X-E mod200
Just example: 303.303 MHz signal, input level ~ -4dBm
As can see  displayed noise floor top is under -80dBm (with this setting, including 50mV/div) and our 303MHz signal is around -10dBm (input level around -4dBm (attenuated roughly 6dB))
If look image 1.3 it can easy estimate what is situation if signal is example 490MHz with this same input level.
Yellow (persistence) is noise floor without trace averaging and white with average 16 traces.
Of course scope input have 50ohm termination and oscilloscope set for 50ohm external load. This Ext load value can set from 1ohm to 1Mohm.



Also compare to Reply #808 test image. Make your own conclusions or guesses. I can - but I do not want - speculate what is this or what it looks like at this point until more data.




Picture 2.
Oscilloscope set for 1GSa/s  1ns/div, Sin(x)/x (later Sinc) on. Display mode vectors and color grade on (reason was better visibility in some other tests for better visibility and then it was on also here without reason)
Signal source Tek 284 pulse generator.   
(~70ns rise time in specifications but of course it is not true here with this kind of reactive load)

As can see in image with 1GSa/s these scopes works just as 100MHz and 200MHz scope work. No bad aliasing visible (if it exist it can see as corners wobbling with this kind of signals).
100MHz model no any visible aliasing but with 200MHz model there can see small amount corners wobbling (mode of aliasing). Note that input signal have lot of high frequency harmonics what goes really far over 500MHz fNyquist. Think user with probes. It is very hard to get these aliasing frequencies in to scope with normal probes when studying conventional circuits in practice. Of course if you make or own fast edge pulser you can... just remember, you can not use these scopes for analyze them and if pulse do not have enough wide real flat top you can not analyze scope with these.
 
But now, just keep it mind that this tests is with 1GSa/s what is available only if one or two channels are in use simultaneously. If three or four channels are in use, maximum is 500MSa/s per channel.
Just one thumb rule. When 500MSa/s in use do not input sinewaves what are more than just bit over 200MHz or pulse/square etc's where exist well under 2ns rise/fall times. Of course you can but then really need to know how to look for results so that aliasing do not fool you. Do not fall in to trap of alias.




Picture 3.
Oscilloscope set for 500MSa/s  1ns/div, Sinc on. Display mode vectors and color grade on.
Signal source Tek 284 pulse generator (as picture 2.).   

As can see 500MSa/s is not enough specially for 200MHz BW with this kind of very fast rising signal when there is not brick wall type analog BW filter in front end before ADC what is only possible place. Digital side it can not do. Even if whoever is dreaming or believe fairy tales.

(later I will show how it looks like using different input signal risetimes what are more normal for use with this kind of oscilloscopes. )
 
With 200MHz model there can see lot of aliasing due to tiny attenuation over fNyquist. Input signal have lot of high frequency harmonics what also have high level and what goes really far over 250MHz fNyquist.

100MHz model rejects these high frequency components more and so aliasing is not at all so heavy.

It is bit stupid to drive these scopes with this kind of signal except for show limits of this kind of scopes. It is good that user understand these things and know his equipment for avoid mistakes when he think what is this machine showing. These things are natural and normal, all match with practice and theory. These are not at all bugs. Only way to avoid these are higher samplerates and or more expensive analog side filters. Of course mostly in practice there come other things what rejects frequencies (rise times) before oscilloscope input BNC.

Remember, 500MSa/s is not good for 1.75ns rise time square/rectangle type input signals but still ok for 200MHz sine wave signals. Only exception is if oscilloscope have reallly "hard-core" bit over 200MHz brick wall  filter. But then also you can not see 1.75nsa risetime on the screen what ever fast risetime flat top pulse you input. Fundamentals stay... 
 
Of course it is nice if manufacturer implement more and better analog side filters and even better if user can select these. But there do not exist free lounges.

If you need analyze signals and measure real risetimes with good accuracy, remember "five times" rule.
If you need measure example 2ns risetime signals risetimes etc and you need measure quite accurately  (~2%) these 2ns risetimes you need oscilloscope + probe what have 0.4ns or more fast risetime.

[rf-loop]

Under construction


First  look picture 3. in previous message. There input signal risetime is lot of under 1ns (generator specified for 70ps when load is perfect)

Next tests are made using generator with adjustable rise and fall times. Also it have quite low risetime jitter. (this is not at all like el cheapo DDS generators. Oh yes this machine have other not so nice things but for this test it is suitable (old heavy HP boat anchor - 100MHz double out programmable pulse generator)

Tests made using 1GSa/s and input signal risetimes 1, 1.8 and 3.5ns
And then same tests using 500MSa/s
in all images scope Acq mode is normal, fast, interpolation Sinc and display mode vectors.
With 1ns input and 500MSa/s  original and specially mod200 version show lot of aliasing and Sinc overshoot due to sample period related to rising edge time.

As told previously, using normal cheap probes it reduce pulse risetime so that scope do not see this kind of risetimes. Also user need know this kind of limits and take care about these basics for avoid false interpretations of what is displayed on the oscilloscope screen. Know your equipment!



Picture 4
As can see with 1GSa/s  Both versions no any problems, just "perfect" even when input is 1ns risetime pulse but of course 100MHz model show far less fast risetime than 200MHz mod.




picture 5
As can see with 1GSa/s  Both versions no any problems, just "perfect" when input is 1.8ns risetime pulse.
Of course 100MHz model show less risetime than 200MHz mod.




Picture 6
As can see with 1GSa/s  Both versions of course just "perfect" when input is 3.5ns risetime pulse
Of course 100MHz model show bit less risetime than 200MHz mod.




Picture 7  (look also Picture 3. in previous message)
Now 500MSa/s. Input signal pulse risetime is 1ns. It is clear that this kind of signal with 500MSa/s is problem. It is problem specially with 200MHz mod due to its bandwidth shape what do not reduce enough frequencies over fNyquist and also importantly, risetime is too fast for this samplerate so that also Sinc interpolation overshoot more and less depending position of true sample points in every single acquisition.
As can see 100MHz model reduce problem due to its BW (risetime).
For reduce overshoot there can also turn Sinc off, what is some times recommended  in the literature for some situations with pulse/square type "digital" signals. But remember also, here we use signal what have risetime (frequencies) what goes over this scope. (1ns rise)




Picture 8
Same as in picture 7 but now with 1.8ns signal pulse edge risetime 200MHz mod show some amount less corners wobbling (form of aliasing due to signal high freq components and some amount Sinc "feature".
100MHz model works just nearly perfect.




Picture 9
Now with 3.5ns signal pulse edge risetime 200MHz mod show only quite small signs of corners wobbling. It is also possible that HP generator pulse edge corners are bit sharp(?)
100MHz model works just perfect.


Using 500MSa/s (more than 2 channels in use)
it is enough for 200MHz, this is not problem at all (this is always defined as sinewave).
But user need understand some these things if signal have meaningful amount of higher frequencies for avoid traps and false interpretations of the signal being tested.  Know basic fundamentals and importantly; know your equipment.

[rf-loop]

Reserved for continue test results in this same context

[rf-loop]

Reserved for continue more test results in this same context

[rf-loop]

Reserved for continue more test results in this same context
Reply #830 updated
Added image 1.3 and 1.4 with some explanations.

[SMB784]

Thanks to the intense efforts of the people over at the Siglent .ads thread, I was also able to modify the software and now my scope performs according to the specifications described by RF-Loop above.

Thanks all!

[SMB784]

Independent confirmation that the software modification provides the claimed 200 MHz bandwidth upgrade.  All measurements taken at 0dBm input signal into 50 Ohm terminator with the same scope.

100 MHz signal has 0.560 V peak to peak amplitude

235 MHz signal has 0.392 V peak to peak amplitude

This corresponds to a 3dB point of 235 MHz, well beyond the 1104X-E's claimed 100 MHz bandwidth, and in line with the 1204X-E's 200 MHz bandwidth.

Pictures (a little blurry now) attached

[rf-loop]

Independent confirmation that the software modification provides the claimed 200 MHz bandwidth upgrade.  All measurements taken at 0dBm input signal with the same scope.

100 MHz signal has 1 V peak to peak amplitude

235 MHz signal has 0.700 V peak to peak amplitude

This corresponds to a 3dB point of 235 MHz, well beyond the 1104X-E's claimed 100 MHz bandwidth, and in line with the 1204X-E's 200 MHz bandwidth.

Pictures attached

This correspondds around -3dB compared to 100MHz level as reference. ... yes, it tell that it is now different compared to original.

But...


0dBm in 50ohm system is: 223.6mVrms (632.4mVp-p) 1Vp-p in 50 ohm system is 3.98dBm
And now, when you get 1Vpp using 100MHz and generator set fore 0dBm  it tells that "some things are wrong".

I can not see 50ohm termination in oscilloscope input!

Generator output impedance is 50ohm. Coaxial also 50ohm.  This transmission line need end with 50ohm impedance. You can test it without termination. Start from example 1MHz and slowly rise freq up to example  300MHz... you get many highs and lows due to reflection between scope input and generator output depending cable travel time.   It is now also depending your cable length now what reading you get with different frequencies.

[SMB784]

This correspondds around -3dB compared to 100MHz level as reference. ... yes, it tell that it is now different compared to original.

But...


0dBm in 50ohm system is: 223.6mVrms (632.4mVp-p) 1Vp-p in 50 ohm system is 3.98dBm
And now, when you get 1Vpp using 100MHz and generator set fore 0dBm  it tells that "some things are wrong".

I can not see 50ohm termination in oscilloscope input!

Generator output impedance is 50ohm. Coaxial also 50ohm.  This transmission line need end with 50ohm impedance. You can test it without termination. Start from example 1MHz and slowly rise freq up to example  300MHz... you get many highs and lows due to reflection between scope input and generator output depending cable travel time.   It is now also depending your cable length now what reading you get with different frequencies.

Whoops, forgot the 50 ohm terminator! New measurements are updated in the original post.

[innkeeper]

i could swear mine did a bit better... I'll have to re-measure now.
my generator only goes to 280 though.

be careful. i find that most signal generators aren't exactly flat on their outputs either.  so double confirm you're getting out what you expect.
i double check mine with an SA i have.

[SMB784]

i could swear mine did a bit better... I'll have to re-measure now.
my generator only goes to 280 though.

be careful. i find that most signal generators aren't exactly flat on their outputs either.  so double confirm you're getting out what you expect.
i double check mine with an SA i have.

The range in my signal generators caps out at 1GHz, and it's rated amplitude flatness is better than 0.5dB. I will test it with my spectrum analyzer tomorrow though!

[TheNewLab]

You guys are way ahead of me regarding increasing bandwidth..Anyone talking about building your own MSO module? SBUS connector? I sure I can find it..Siglent's version

[toli]

Siglent didn't get their MSO right,so I hope you can do better
But it sure sounds like a nice idea, there are many things you could do better than the original unit.

[SMB784]

So I must say that I am very impressed with this scope, especially with the extended bandwidth. Definitely an amazing value for the price.

One thing that I have noticed is that when I am using multiple channels, I would really like to have the channel buttons for each channel being displayed to be lit up, e.g. if I am measuring waveforms with channels 2 and 3, I would like the physical buttons to be lit up for channels 2 and 3. I realize that this might conflict with fact that the active channel is lit up, but perhaps the active channel button could cycle between a bright and dim state to accommodate that feature.

[tautech]

So I must say that I am very impressed with this scope, especially with the extended bandwidth. Definitely an amazing value for the price.

One thing that I have noticed is that when I am using multiple channels, I would really like to have the channel buttons for each channel being displayed to be lit up, e.g. if I am measuring waveforms with channels 2 and 3, I would like the physical buttons to be lit up for channels 2 and 3. I realize that this might conflict with fact that the active channel is lit up, but perhaps the active channel button could cycle between a bright and dim state to accommodate that feature.

While that's not a bad idea, lighting in a workplace present or not could effect the usability of dual illumination of buttons. I suspect it couldn't be done with SW but we'd have to check the front panel HW to know for sure.

While I've never been a fan of multiplexed vertical controls I quickly came to grips with X-E UI and use both the channel buttons and channel OSD indicators to know which channel is active for the controls and which are ON.
I'm certain the familiar GUI helped me immensely.
Old habits die hard and I get that if you're used to a certain UI it does take some time to change.
I commonly use 3 different Siglent DSO's and they all have minor differences in the UI but just that keeps my mind 'on the job' so not to make dumb arse errors.
I guess we all have different workflow and unlike a scope with dedicated vertical controls and and their ON/OFF illuminated buttons I think Siglent have picked an effective compromise for an entry level DSO.

Thanks for your feedback and maybe this subject can be explored further for some solution that might suit you better.

[rf-loop]

This is one useful "Know your equipment" thing.

One question what some times rise up is need for keep trigger horizontal position  in some other (user selected) fixed position than screen center what is many times default and only choice in lower end scopes exept example Siglent SDS1kXE.
Many my old (digital)scopes what I have used past decades, including some Tektronix and HP have user selectable horizontal position (zero time) so that when change horizontal speed it keep this position. Least so that there is three options, left or near left, center, right or near right.  And, this is useful many times.

Of course if it is only center, as in many entry level digital scopes it is, it is not "show stopper", quite easy you can move horizontal position (delay). But some times it is very frustrating when you need change time base and after every change you need adjust horizontal position (delay)
(and this same is also vertical what have offset and vertical display position. Change V/div and always adjust position again.. )

Just as @mikeselectricstuff say here.
https://www.eevblog.com/forum/testgear/micsig-to1104-wishlist/msg1397471/#msg1397471

Something that Chinese scopes like this often omit is to be able to have the zero-reference at the left or right (1 div from edge) of the screen as additional options to having it at the the centre.
You are almost always most interested in what happens before OR after the trigger, so these make more sense than having it at the centre.

Siglent SDS1104X-E have this feature with fully variable horizontal fixed position instead of some fixed positions.
User can select "Reference positions"
For Vertical: Fixed Position/Fixed Offset (factory default: FP)
For Horizontal: Fixed Delay/Fixed Position (factory default: FD)

If I set horizontal for Fixed Position, say example 5 div before center (2 div after display left)
after then when I change t/div it keep this position.

If I set horizontal for Fixed Delay. Scope default is that it is center screen. Now if have, say example 1us/div, and I want look more things after trigger I can move horizontal of course so that it have trigger position example -5us from center.  Now I can see 1 div before trig and 12 div after trig.  But then, I want change time base to example 100ns/div. Now my trigger position is far left out from display and I need turn adjustment until trigger position is visible. Then I go back to 1us/div and adjust again. Very frustrating if need do this.  Of course Fixed Delay is good for many things but not fore all.

Just select fixed position and now it keeps trigger horizontal position in place what user want. Left or Right or what ever position user want.

It also keep this selection until you change it or recall defaults (exept if you have changed defaults what you also can do)

(and same for Vertical. Very useful to use fixed Offset if you have signal what have DC offset and then you need look it with different V/div settings. You change V/div and your displayed signal stay in nsame vertical position (yes AC coupling can use, except if you are also interested very low frequencies down to DC)

(But least I'm not satisfied with horizontal Fixed Pos mode. In this mode my opinion is that displayed delay time zero is better to keep in this user adjusted fixed position, not center of display.  Of course this is only my personal opinion but so or so it is not rocket science to change it)

Here is one simple tiny example.
Signal is saw tooth with fast rise and slow fall.
I set Fixed Position 2 div from left side.
Then I have only changed time base from 10us/div to 1ns/div. And it keep its position on the screen. (with fixed delay it keeps position only if trigger is display center)
(due to very long persistence time you see all time base settings)

[GregDunn]

Thanks to the community for the amazing reviews, updates and general info about this scope.  Is there a manual which specifically addresses the 1x04 4-channel models?  All I can find on the web is a 1x02 series manual which has been edited to include a few references to the 4-channel series.

I know 90% of the details are the same, but there are a few idiosyncracies of managing the shared vertical controls which are puzzling me and aren't talked about in the manual (which assumes separate vertical controls for each channel).

[17_29bis]

Hi,
I wonder what I am observing here - a bug in the latest stock firmware (7.0.6.1 25R2) or something else. I noticed that every time when I zoom in (change vertical sensitivity) on the recorded signal it looks quite noisy. Eventually I simplified  the test to avoid any ambiguity and this is the result:

a) the signal source (MCU) with stable power supply generates 50 pulses. The channel 4 monitors power line. The SDS1204X-E is single trigger mode, 5V/div, the signal is applied to channel 1



b)now lets change the scale to 1V/div - the signal looks quite noisy and I know that this is not true.





c) another recording of the same signal, SDS1204X-E is in single trigger mode, 1V/div, the signal looks as it should be. The only difference a c is the vertical sensitivity.



My question is - what is this wrong with displaying the previously recorded signal when the vertical sensitivity has been changed ?
Thanks!

[tautech]

Thanks to the community for the amazing reviews, updates and general info about this scope.  Is there a manual which specifically addresses the 1x04 4-channel models?  All I can find on the web is a 1x02 series manual which has been edited to include a few references to the 4-channel series.

I know 90% of the details are the same, but there are a few idiosyncracies of managing the shared vertical controls which are puzzling me and aren't talked about in the manual (which assumes separate vertical controls for each channel).

Yep, the US site hasn't been updated with the latest version of the manual but it's available from the Shenzhen site even though the URL appears to indicate otherwise.
http://old.siglentamerica.com/USA_website_2014/Documents/manual/SDS1000X-E_UserManul_UM0101E-E03A.pdf

[GregDunn]

Excellent - that's updated and much easier to follow.  Much appreciated!

[tautech]

Hi,
I wonder what I am observing here - a bug in the latest stock firmware (7.0.6.1 25R2) or something else. I noticed that every time when I zoom in (change vertical sensitivity) on the recorded signal it looks quite noisy. Eventually I simplified  the test to avoid any ambiguity and this is the result:

My question is - what is this wrong with displaying the previously recorded signal when the vertical sensitivity has been changed ?
Thanks!

I know there are occasions when a STOP, Single or screenshot displays things that take some understanding so just trying to find a reason for what you see:
Can you set Ch4 to AC coupling and crank up the sensitivity ? 5V/div doesn't tell us much.
Could the the noise you see on Ch1 be related to the MCU clock ?