TESTS: Siglent SDG5082 Function/Arbitrary waveform generator. (+Inside images.)

[rf-loop]

I will update more tests results after they are ready.  So, this is as "under work"!


Siglent SDG5082 is member of SDG5000 serie. There is 80, 120 and 160MHz models. This is 80MHz model.
Specs and features can read from SDG5000 User Manual, Data sheet and Service manual.







There is plan to test lot of things so that also results are enough accurate and reliable test data.
It takes time. One reason is that I do it just like hobby and priority is "after more important things".
Also all equipments and accessories, used for tests,  need some kind of accuracy check so that least I can trust results. Also some tests setups need rearrangements in my workshop because there is running also other things.Which order I show tests results do not mean the order of importance for me or any others. One of the test may also be one that someone has requested it.

I do not (very often) tell if some thing is good, nice, exellent, crap, bullshit or other just my opinion.  I take more this the approach angle that I show test data and perhaps later also some other details. You look data and make your own conclusions. But also, compare to other equipmenst is difficult becouse there is not so much available real tests.


Of course I can tell if I want that oh this is...  and oh that is.... and this is nice and best and all superlatives to positive and/or  to negative direction as oh what shit...specially if do not know how to ,measure and how to use equipment what I'm testing. But there is enough this type of tests...so... it is not for  me.  Yes, if I need equipment I do it inside my mind  for my self and related to my needs and also related to what I like and what not... specially in UI. 
You look data and make your own thinking.
I try keep data as reliable as possible. If you see something wrong in data or measurements please inform me. I try explain better or just correct it.


Here first frequency response from around 300kHz to 80MHz.
SDG5082   0213 manufacture, FW:5.01.01.07R1
HP8568B  Spectrum analyzer.  (this flatness is good but absolute level may have some small error specially between different RBW (some fraction of decibel). Also horizontal scale may have small errors and this is not now connected to external accurate freq reference.
BNC - N adapter (Suhner)
~1.5M  NEK  M17/084
Images from HP8568B/HP-IB  to  USB/PC by Prologix 6.0 adapter and KE5FX GPIB Toolkit.


SDG5082   set for +13dBm output. (of course 50ohm)
Sinewave.
Freq Sweep made by hand using SDG knob with small steps.
HP8568B  mode  Max Hold. (for clarify: something like "Peak hold mode")



~1MHz  - 80MHz   Note that level scale is 1dB/div
(with this scale and near zero freq  RBW affect so that "zero" start show just near left side (<2MHz, just do not care it)




300kHz - 10MHz. (note small level difference between first image. This come from different RBW filter. Inside one picture analyzer (+ cable) itself flatness is very good so markable part of quite small level deviation come from device under test.) Note that level scale is 1dB/div!


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




Here  80MHz sinewave  with maximum output level, +17.9dBm
Spectrum display mode: Max hold!






10.7MHz  level +13dBm   
Spectrum display mode: Max hold!







50MHz   level -47dBm (1mVrms)
Spectrum display mode: Max hold!





10.7MHz  and maximum level +23.9dBm, overview of harmonics and non harmonics.
(3th harmonic around -45dBc)




10.7MHz  and level +13dBm  overview of harmonics and non harmonics.
(3th harmonic around  -50dBc)

Sometimes here may find some more test images and data or something more detailed information.

[rf-loop]

For compare, here one sample from old SDG1025 test (one yar ago)
11MHz and level +17dBm
also here spectrum RBW 10kHz 



Of course SDG5000 have better signal, this is natural.

[rf-loop]

Some test for Voltage levels (DC offset)
Not, if you use it for DC source:
Remember it have 50ohm source impedance.  This is not "power supply".





Frequency accuracy (internal reference clock in use) measured just after  DC offset voltages test.
HP53131A  connected to GPS OCXO  (GPS OCXO stability is not now best possible, so this continuous fluctuation up and down is included and unknown.
CH1 out 10MHz Sine  +13dBm
watching time around 1 hour.  (10s gate)
Min  10.000 000 868
Max 10.000 000 971 

Short time tests, just one shots using 10s gate.
33MHz out:  result 33.000 002 88
50MHz out:  result 50.000 004 49
80MHz out:  result 80.000 007 36
100kHz out: result 100.000 009 19 (kHz)




To be continued.......  (the next few days is busy with other things)

I hope I can show soon tests results about square wave signal quality.
(It is really different s SDG1000)

[maiakaat]

It looks good so far

[rf-loop]

Some test samples.

I have been interest about SDG5000 square waveform quality.

These images are self explanating.





Note: SDG1025 test with ~10kHz and SDG5082 picture test freq 1kHz



SDG1025 time jitter. SDG5000 series is totally different.
Still it is good to note that SDG1000 jitter is as specified.
This is cycle to cycle random +/- jitter and not long time cumulative.

 



SDG5082 Square Wave time jitter is naturally better than SDG1000 series
(naturally, becouse circuits principle is totally different. Not derived from internal sinewave using comparator method as very usual in this class. Note: If need less jitter, SDG1000 can use Pulse mode for produce square wave. With low frequencies it have less timing jitter. Higher frequencies, Sguare wave have less jitter than Pulse. Pulse have always 8ns jitter due to 125MHz clock.)





SDG5000 Pulse Mode. 5MHz 50% duty. (rise and fall time adusted. Minimum value 6ns)
Edge rise and fall time is separately adjustable!
NOTE: In picture read Square Wave. This is wrong.
Edges can adjust in PULSE mode!!

[rf-loop]

Siglent SDS oscilloscope  captured waveform can move to SDG5000 and then repeat.
Later more about this feature.

Simpliest it can do so that save captured waveform .csv data to USB  and then move USB stick to SDG5000 and read this .csv data to Arb memory. Just then select this stored Arb waveform for output. With SDG5000 level, offset and frequency adjustment you can scale it so that output waveform is equal what was captured using Siglent oscilloscope.

Tested and works without problems.
This was simple method.

But later I will give also information with some tests about:
SDG5000 "Seamlessly work with SIGLENT Digital Storage Oscilloscope"

[rf-loop]

What is the build quality like? I have heard some Siglent stuff is not that good, while other products are excellent.

Externally, build quality seems good. Of course, if the device would cost ten times more, I would like that the connectors are genuine Suhner, Rosenberger, or other very high quality. Possibly even the entire structure could be a die-cast aluminum. It is good, however, to relate to the requirements of what is the price.

As I said before, I'm not going to typeset positive or negative superlatives in all sorts of astonishment expressions. Siglentin common way to protect the surface of the TFT gets me, however, + points.
I do not make tear down rewiev show business where only "boss" is the popularity without any standards.

Instead, in the near future I am going to present some boring documentary photos of the device inside and out.

And of course more test data with some test pictures.

Now it is running  frequency stability tests so I can not touch it.

[rf-loop]

Here some pictures from inside.
More pictures and also detailed pictures coming later.

In first image, just top side of grey ribbon cable there is 3 big IC's.
They are Analog Devices ADUM1410 isolators.
(Main output (CH1, CH2) GND's are floating from equipment ground, max 42V)


Just top side of "big" heatsink can see main DAC (500Msa 14 bit double DAC)
Analog Devices AD9781.

Next picture can see output amplifiers. Both channels are similar.
Outputs have SMB connectors.

Left from wide grey ribbon cable is frequency reference. Xtaltq Technologies, BT0507 series 10MHz TCXO. 

TCXO specifications meets well Siglent specifications for SDG5000 series.

It can also note that this TCXO have fine adjustment control. (pin1)



Overall all PCB's are extremely clean and no any signs about hand soldering.

Work has been done on the whole very carefully.

Minor class note: The wires that come from the power supply side would have protected the insulating sock (if I do it). On the other hand corners are rounded so the insulation is not the risk of breakage. (as long as the door is closed so that the wires are in the correct position) Work has been done on the whole very carefully.
The wires that come from the power supply side would have protected the insulating sock. On the other hand corners are rounded so the insulation is not the risk of breakage. (as long as the door is closed so that the wires are in the correct position) Also, just a cable tie would help.

[maiakaat]

Looks like they've used decent caps in some of it too

[rf-loop]

Here some more images from inside.

Later I will give link to full size images if anyone is interested.


PSU.  Looks like all dark color electrolytics are Rubycon 105 degree.
Big white power connector is for Channel board
Small two pole white connector is for Main board



Main board.



Channel board.  Note that both channels have equal end amplifiers including driver amplifier. (in SDG1000 series CH1 and 2 amplifiers are different) Also outputs are floating from equipment ground. Note also isolated connection between main board and channel board. (Analog Devices Digital signal Isolators 3x ADUM1410. Main DAC is AD9781  2x500MSa 14bit)
On the board is default TCXO. It looks like there is also ready place for better reference.



Front panel.



Frame etc.

For some mechanical construction and test point details, look Service manual (available from Siglent download center)


Bigger size picture example from PSU top.

[rf-loop]

Here one medium resolution sample picture from Channel board output amplifiers.
Note that outputs GND is floating from chassis ground. (Max 42V but this can stop some ground loop currents between equipments).  Output power is 4 times Rigol 4000 example between 20MHz to 40MHz. (specs)

Soon I will continue tests after I have assembled unit exactly back to its original factory state.

[rf-loop]

Some amount more accurate test for internal 10MHz frequency reference (default reference TCXO) frequency accuracy and hours level stability. Measured from rear panel  frequency reference output.




Available output levels compared to Rigol DG4000 series:
Sspecially between 20-40MHz difference is big. 4 times more power.

[rf-loop]

Before I go to other tests this one odd finding. Not problem, but user is important to know.

About rear panel 10MHz Reference input and output. This I find when I work with frequency accuracy tests.

Utility --> System and there side 2/2.
CLKSource
Internal
External

Internal:

Internal 10MHz reference (TCXO) is selected.
Rear panel "10MHz In" do not affect.
Rear panel "10MHz Out" have internal frequency reference frequency.

External:

External reference is selected and there need be valid clock available.
Rear panel "10MHz In" frequency is used as frequency reference.
Rear panel "10MHz Out" have internal frequency reference frequency.

- External clock need be least same or better quality (stability, accuracy, phase noise/jitter) than internal reference, in other case equipment specifications are not valid.


Attention:

Rear panel "10MHz Out" have allways internal frequency reference frequency.
Also in case that equipment is working with external reference clock.
If you use external reference also to other equipments, it can not take out from this output.
In general, chaining is not a very good way to share your reference in lab. Therefore, this is not a big problem. But the device, however, is unusual in this respect. It is good to remember when using the device.

I recommend that if this is used in lab where also is external  frequency reference for use. Add some kind of note to rear panel that "10MHz out" give allways internal TCXO reference frequency out independent of what reference is in use.

Also, on the display, there is not any indicator what can always see that equipment is satisfied locked to external frequency. (there is not even check if external clock is valid or not, it just work out of order if external freq is selected and it is out of order. On the TFT there is lot of free room for this kind of continuous indicators as normally in many equipments what have internal or external reference.)

It is not problem or fail. But  user need carefully know that all is ok with reference for avoid mistakes if do some frequency critical things.

[jpb]

Before I go to other tests this one odd finding. Not problem, but user is important to know.

About rear panel 10MHz Reference input and output. This I find when I work with frequency accuracy tests.

Utility --> System and there side 2/2.
CLKSource
Internal
External

Internal:

Internal 10MHz reference (TCXO) is selected.
Rear panel "10MHz In" do not affect.
Rear panel "10MHz Out" have internal frequency reference frequency.

External:

External reference is selected and there need be valid clock available.
Rear panel "10MHz In" frequency is used as frequency reference.
Rear panel "10MHz Out" have internal frequency reference frequency.

- External clock need be least same or better quality (stability, accuracy, phase noise/jitter) than internal reference, in other case equipment specifications are not valid.


Attention:

Rear panel "10MHz Out" have allways internal frequency reference frequency.
Also in case that equipment is working with external reference clock.
If you use external reference also to other equipments, it can not take out from this output.
In general, chaining is not a very good way to share your reference in lab. Therefore, this is not a big problem. But the device, however, is unusual in this respect. It is good to remember when using the device.

I recommend that if this is used in lab where also is external  frequency reference for use. Add some kind of note to rear panel that "10MHz out" give allways internal TCXO reference frequency out independent of what reference is in use.

Also, on the display, there is not any indicator what can always see that equipment is satisfied locked to external frequency. (there is not even check if external clock is valid or not, it just work out of order if external freq is selected and it is out of order. On the TFT there is lot of free room for this kind of continuous indicators as normally in many equipments what have internal or external reference.)

It is not problem or fail. But  user need carefully know that all is ok with reference for avoid mistakes if do some frequency critical things.

Won't the internal reference be phase-locked to the external reference if there is one, so the accuracy of the internal reference should match the external one? The Siglent specification lists a lock time of < 2s implying that this is what they do.

Daisy chaining might not be optimal, but for home lab users with limited space and budget for distribution amplifiers it is a convenient solution.

[rf-loop]

Before I go to other tests this one odd finding. Not problem, but user is important to know.

About rear panel 10MHz Reference input and output. This I find when I work with frequency accuracy tests.

Utility --> System and there side 2/2.
CLKSource
Internal
External

Internal:

Internal 10MHz reference (TCXO) is selected.
Rear panel "10MHz In" do not affect.
Rear panel "10MHz Out" have internal frequency reference frequency.

External:

External reference is selected and there need be valid clock available.
Rear panel "10MHz In" frequency is used as frequency reference.
Rear panel "10MHz Out" have internal frequency reference frequency.

- External clock need be least same or better quality (stability, accuracy, phase noise/jitter) than internal reference, in other case equipment specifications are not valid.


Attention:

Rear panel "10MHz Out" have allways internal frequency reference frequency.
Also in case that equipment is working with external reference clock.
If you use external reference also to other equipments, it can not take out from this output.
In general, chaining is not a very good way to share your reference in lab. Therefore, this is not a big problem. But the device, however, is unusual in this respect. It is good to remember when using the device.

I recommend that if this is used in lab where also is external  frequency reference for use. Add some kind of note to rear panel that "10MHz out" give allways internal TCXO reference frequency out independent of what reference is in use.

Also, on the display, there is not any indicator what can always see that equipment is satisfied locked to external frequency. (there is not even check if external clock is valid or not, it just work out of order if external freq is selected and it is out of order. On the TFT there is lot of free room for this kind of continuous indicators as normally in many equipments what have internal or external reference.)

It is not problem or fail. But  user need carefully know that all is ok with reference for avoid mistakes if do some frequency critical things.

Won't the internal reference be phase-locked to the external reference if there is one, so the accuracy of the internal reference should match the external one? The Siglent specification lists a lock time of < 2s implying that this is what they do.

Daisy chaining might not be optimal, but for home lab users with limited space and budget for distribution amplifiers it is a convenient solution.

This is quarenteed time for unit lock to external reference.
It looks like it do not adjust internal TCXO. In case there is external clock this internal TCXO live its own independent life and it is not used to system at all but still it is available from 10MHz output connector. (and if disconnect external reference when it is selected for use, equipment have not at all clock (on the channel board and signal is out of order or no signal)
Of course main board ("brains") have its own clock)

I will loater check this agen but I think I have not made mistake. (also I have done external clock sweep (+/- 100kHz 10MHz) and equipment follow it. Internal TCXO do not follow it so it is overrided. Also TCXO adjust pin voltage looks like stay steady (1.52V)

So, this 10MHz output can use for syncronize other equipments but only IF internal reference is in use. (test data table can find some idea about its accuracy, what is well enough for many ordinary purposes) If need external reference and if want in this case syncronize also other equipments then reference need share other way than chaining exept if this unit is last in chain.

[jpb]

Thanks for taking the trouble to do those detailed checks.

It seems a strange decision by Siglent to neither phase lock the internal TCXO nor to simply switch the external through a buffer to the output (which is what TTi do with their TG5011 whilst Agilent I think phase lock their 33520 as they list frequency range specks for the external reference which are different depending on which internal oscillator you have fitted).

As you say, it is not a big deal as long as you know. The main purpose of the external output would seem to be to keep a check on it with a frequency counter perhaps. Most other equipment with the option of an external frequency standard input probably already has at least as accurate an internal oscillator. Getting two generators in synch might be useful.

[rf-loop]

Some random tests.
Arb pulse tests is small part of tests for analyze  Arb functions, later some more about its frequancy responses etc more detailed things.



ARB 16834ns cycle. Starting of ARB,  first 128ns pulse.
SDG5082 set for 16834ns cycle time.
(Oscilloscope used here is SDS1102CML, oscilloscope input terminated with 50ohm feed thru, before feed thru there is also 10dB 50ohm attenuator (Suhner) and some adapters becouse I do not have so much things with BNC, nearly all stuffs are N or SMA)
SDG output level adjusted then for around vertical 6 division display.



ARB cycle time changed 16384, 8192, 4096, 2048, 1024 and 512ns
Of course then pulse wide change proportinally 128ns, 64, 32, 16, 8 and 4ns.
Note that waveform generator sampling speed period is 2ns (500MSa/s)
Scope persistence infinite.




Same ARB as before. (16384/128ns)
Cycle time now 2000ns.  (500kHz)




Same ARB as before
Cycle time now 2001ns.
Now there can see bistable jitter. Just 2ns becouse sampling interval is 2ns and it need adjust for  "average" freq /cycle time.




100kHz triangle. Duty "zero".



100kHz triagle (dyty "zero") rising edge.




Pulse risetime and also fall time (both separately of course) can adjust with fine steps.
(note that falling edge have moved some amount  becouse trigger position is not precisely right point when I adjust edge risetime)



It can produce fast pulses with fast risetimes also if there is used very low frequencies. Here 12ns to 60ns pulses and frequency 20Hz. And it really can adjust with 1ns steps even with these low frequencies! Also it keep risetime.
Edges and pulse width adjusting resolution is down to 100ps.
Siglent name these new features as EasyPulse:

"SDG5000 adopts Siglent original technology EasyPulse, not only enhance the hardware index but also improve the software. It can output high quality, high flexible pulse signal: 100ps low jitter, ultra wide duty-factor range: 0.0001% ~ 99.9999%, quick rising/falling edge 6ns ~ 6s, edge and pulse width precision can be adjusted: 100ps resolution.SDG5000 can meet different application situations."

But this 100ps low jitter is better to read as "down to 100ps"

I will later analyze better this jitter. Also I'm not interest about "rms" jitter as long as this value is proofed  with some unknown method. Time jitter is difficult case.

One approach is measure long time maximum peak to peak jitter over one cycle.
But these numbers are not nice.
 
Many manufacturers tell "rms" value for jitter (and perhaps just from 1SD).
Very simple and  nothing real or related to this equipment, example. It there is 9998 samples zero jitter and then one -10ns and then one +10ns. What is now rms jitter. In my some circuit rms jitter is not meaningful but  these peak values may really do bad things and even kill peoples.

And now this is difficult. Example I do not have any equipment what can take exactly 10000 samples sequentially (every cycle example) and analyze this distribution.

I understand well why manufacturers, example Agilent,  argumenting for rms values. It is nice to write specifications with nice looking numbers but more important is that most of users can not proof if equipment do not meet advertisements or specifications.


Attached also  (just change .txt to .csv if want use it) used for this Arb tests. (both channel give same result with this same 16k csv.)
(Ch2 have also 500k but not yest tested, just only played some funs)

[rf-loop]

Won't the internal reference be phase-locked to the external reference if there is one, so the accuracy of the internal reference should match the external one? The Siglent specification lists a lock time of < 2s implying that this is what they do.

I will loater check this agen but I think I have not made mistake. (also I have done external clock sweep (+/- 100kHz 10MHz) and equipment follow it. Internal TCXO do not follow it so it is overrided. Also TCXO adjust pin voltage looks like stay steady (1.52V)

I have tested this carefully agen.

10MHz reference output have allways internal reference frequency. Also if external reference is selected for use. 

In test
SDG5082
HW: 00-00-00-13-34
FW:5.01.01.07R1

If use external reference for many equipments and reference is chained via equipments this SDG need be last in chain. Of course this chaining is not recommended way to do it.
Normal and better way is distribution amplifier where all lines are also isolated from ground and each others.

If need external reference. This internal TCXO keeps it well inside specified +/-2ppm including initial error and if trust TCXO manufacturer datasheet, it also include long time drift.

[rf-loop]

There is  coming (slowly) lot of more test results about SDG5000 but it takes time becouse also tests need some revise before show for avoid bad mistakes and mostly it need double or triple tests with alternate methods or other check for better credibility.

[phatcenter77]

Here one medium resolution sample picture from Channel board output amplifiers.
Note that outputs GND is floating from chassis ground. (Max 42V but this can stop some ground loop currents between equipments).  Output power is 4 times Rigol 4000 example between 20MHz to 40MHz. (specs)

Soon I will continue tests after I have assembled unit exactly back to its original factory state.

Can anybody identify the ICs in the output stages in groups of 4? 

The single device in each channel is a VCA824, programmable gain amplifier, from TI:

http://www.ti.com/product/vca824

I googled the markings on the others, but haven't found anything...

[jpb]

Can anybody identify the ICs in the output stages in groups of 4? 
I googled the markings on the others, but haven't found anything...

They are op amps from TI (the data sheet says they are designed for arbitrary waveform generators amongst other things):

http://www.ti.com/product/ths3095

[rf-loop]

Some test about Square wave time jitter between 100ms - 100us period range.
(note that std dev result is perhaps wrong due to lack of enough resolution in HP53131A counter. It need Agilent 53230A or for more accurate result, becouse this jitter is so small)

Typical data collectoion time for single measurement was >5min due to dead time between time intervals. (N=10000)

But test give some imagine that it have quite low jitter.

(In one Siglent document sdev was measured using over 23MHz freq and there result was under 90ps)

[jpb]

Jitter is one area in which the Siglent and the Rigol DG4162 differ. The Rigol doesn't use comparators (I think) so the jitter is determined by the worse case of the sampling cycle period and the square wave period differing by half a sample spacing so that the rms jitter becomes one quarter of the sample rate or 500 psecs for a 500MS/s clock.

Siglent state 100 psecs rms jitter for both pulse and square (with a much worse 2nsec peak for arbitrary), this is consistent with using a comparator to generate square waves from sin waves as is done in the Agilent 33250.

[rf-loop]

Jitter is one area in which the Siglent and the Rigol DG4162 differ. The Rigol doesn't use comparators (I think) so the jitter is determined by the worse case of the sampling cycle period and the square wave period differing by half a sample spacing so that the rms jitter becomes one quarter of the sample rate or 500 psecs for a 500MS/s clock.

Siglent state 100 psecs rms jitter for both pulse and square (with a much worse 2nsec peak for arbitrary), this is consistent with using a comparator to generate square waves from sin waves as is done in the Agilent 33250.

Rigol specification about jitter is:
Square, Pulse and Arb:  (typical)
<5MHz  2ppm+500ps   rms 
>5MHz  500ps  rms
(and it do not tell just anything about real peak values (as usual with many manufacturers)

If only tell rms time jitter, it do not tell much about peak error.
If I give (bad) example 9996 pcs  1ms cycles perfectly  and then there is randomly 2 cycle 10ns  too long and 2 cycle 10 ns too short periods. What is rms jitter or sdev? Still minimum cycle time and maximum cycle time difference is 20ns (-peak to + peak).

500ps typical rms jitter is what seller want write and buyers read with dreams.
These some parameters about jitter distribution  are also good to know but still I need live between peak values.

SDG1000 series use comparator for produce square wave from internal sinewave, same sinewave what is used if output is sinewave. And it can see also in measured data extremely clear!

SDG5000 is different. I do not know exactly how square is produced.,  It can see also in this table and becouse this  it really can not be simple comparator method from sinewave - I think it is clear.
 
And more, these sdev values are not accurate due to HP53131A lack of resolution. I can only suspect that true sdev is  less. 

But, it is nice to see even some kind of test about Rigol DG4000.

Also, do it have 100ps setting resolution for rising or falling slope or same resolution for pulse width also with low frequencies.

----------------------------
Edit: Added:
I have measured also with other method. (but I have
But this is under rework becouse I suspect problem/error in this measurement. It need revise.

Please, do NOT TRUST this table. I have classified this junk status - so far.I suspect that this HP scope have some lack of accuracy if use long delay times. (lot of more delay time after trig point  than capture memory is, for show next rising edge. And perhaps this long delay time is not enough accurate??)


With short delay times it give totally different results and there measured sdev  is well under 100ps.

Also, it is not exactly as real cycle to cycle jitter measurement..
It is only time variations between two rising edges.

Later I will do new tests. 
Edit: False table removed. (there have been problem in test setup)
-----------------------------



This table what is made by using HP53131A is more reliable but it may give too bad sdev values but resoöution for this kind of test is too low.

[phatcenter77]

Can anybody identify the ICs in the output stages in groups of 4? 
I googled the markings on the others, but haven't found anything...

They are op amps from TI (the data sheet says they are designed for arbitrary waveform generators amongst other things):

http://www.ti.com/product/ths3095

Thank You.  I guess if I would have googled opamp 3095 I would have found that, I feel a bit foolish for not trying that haha.  Not surprising that they're using a THS series part from TI.

Great work on characterizing the performance of this AWG. 

[rf-loop]

New test images about SDG5082 Square wave period jitter.

Here some samples  frome new test after some test setup checking.
And it is period jitter, not cycle to cycle jitter. (ref  SiTime, SiT-AN10007 Rev. 1.0)

SDG5082 free run with its own TCXO reference.
HP oscilloscope free run with its own internal reference.

First two images with same test setup using extremely low jitter and low drift 10MHz signal using 9ms and 2ms delay from trig time position. (vertical adjusted for around sime rising angle what SDG5000 rising is nin trigger level. (reference signal is 10MHz  nearly sine)
All under 2ms delay time give same or better result than this 2ms.

Capture time in all images is 150s.  For long period times it capture less samples but in other hand, markable more than 150s capture time may lead too big amount of frequency references drifts and may give  false peak to peak.
Scope display infinite persistence.

Other images, SDG5000 CH1 (CH2  is equal) to oscilloscope using oscilloscope internal 50ohm impedance.

note about images 2 and 3. You can see in image 2 what result it give for extremely low jitter signal. (so part of jitter/drift is from HP oscilloscope with longest delay times after trigger)

Note about last image. It is one of "golden frequency". (what give extremely low jitter)

Image 4. 255us cycle time.
min-max period time 1.8ns  and  sdev 58ps.
capturing time 150s.
Cycle time is 255000ns. If time error distribution is symmetric it means 0.9ns + or - error from "ideal time".
it is around 3.5ppm from cycle time.  (0,00035%)

[rf-loop]

Small test about Arb jitter.

Signal is ARB where is 128points

high and rest of 16384 points low.
(512k memory give compatible results)

Capturing time in both pictures 10 minutes.
Scope persistence infinite.


Picture 1.

Period time is 9.999ms
max-min time (peak to peak) 6ns
stdev is 1.064ns
Stdev is high becouse distribution looks have two peaks around  +/- 1ns from ideal time.

Period time ~9999000ns
sdev is 0.11ppm
-peak to +peak is 0.6ppm (0.00006%)
If distribution is symmetric to ideal time,  peak max time error is 0.3ppm.


Picture 2.

Period time 51us
max-min time difference 2.4ns
sdev 91ps
As it can clearly see distribution is not symmetric.

[rf-loop]

More explanation for picture 1 about Arb jitter.
(other functions work different. Example if you do some pulse using Arb, it may need jumping for adjust example frequency.  It may need also +/- 2ns jumps in pulse width. 
But pulse mode works differently. You can se example pulse wide with 100ps resolution! Ands it keeps it independent of frequency. Also you can  adjust rising and falling time, agen with 100ps resolution. With low jitter and with this feature Siglents own EasyPulse technology is very nice.)


Here picture 3.

I told that jitter distribution have two peaks (with this period time!).
Here is proofment.
This picture is short time capturing so that more rare parts of distribution do not fill whope p-p jitter area. Here these two peaks can clearly see. (around double peak gaussian distribution)
Peaks are around -1ns and +1 ns from total mean value. (of course it fully explain sdev result)

It need remember this is 500MSa/s sampling  machine. And middle values between 2ns raster it need do by "hopping".  If I connect frequency counter with some reasonable gate time I get just right frequancy. 
This "distribution"  is very very different in different period times (frequencies) as can see also in picture 2. (but this same 2ns is also visible there, if capture short time, sometimes even example 30seconds, there can not see this 2ns hop for adjust average period time. If there is way for fine adjust clock instead of this hopping, it may give lot of less jitter. In this price class, I have not seen any with these all other features)
 
So it is good to understand that with this need live if use this equipment in ARB mode.

But if you overall (all waveforms) accept much more jitter, well there is also Rigol 4000 available. (ref. Rigol specs),


Picture 3. is just same all settings as picture 1. but capturing time is lot of more short.

[jpb]

I did some analysis to work out where the Rigol 500psecs or rms jitter comes from. Here I think that they carry over the surplus phase to the start of the next cycle - what I mean is if the sample step is dT and the wave length of the arb (say a square pulse) is 10.3*dT then it will do 10 samples and start the next cycle with a phase offset of 0.7*dT in the phase accumulator.

The worse case jitter is when the remainder is 0.5*dT so it starts odd cycles with 0.5*dT phase and even cycles with 0 phase so there is a peak-peak jitter (for a vertical edge) of 0.5*dT every odd cycle. This gives an rms jitter of 0.25*dT which 0.25*2nsecs = 500psecs which is what Rigol quote.

From your measurements and Siglent's specifications it looks as if they do something different as their peak-to-peak is dT rather than 0.5*dT. Perhaps they start (or have to start) each cycle from zero and to get the correct average frequency they adjust the value of the phase step per dT on different cycles. So in my example of a wavelength of 10.5*dT they would do one cycle of exactly 10*dT and the next cycle of exactly 11*dT.

[rf-loop]

I did some analysis to work out where the Rigol 500psecs or rms jitter comes from. Here I think that they carry over the surplus phase to the start of the next cycle - what I mean is if the sample step is dT and the wave length of the arb (say a square pulse) is 10.3*dT then it will do 10 samples and start the next cycle with a phase offset of 0.7*dT in the phase accumulator.

The worse case jitter is when the remainder is 0.5*dT so it starts odd cycles with 0.5*dT phase and even cycles with 0 phase so there is a peak-peak jitter (for a vertical edge) of 0.5*dT every odd cycle. This gives an rms jitter of 0.25*dT which 0.25*2nsecs = 500psecs which is what Rigol quote.

From your measurements and Siglent's specifications it looks as if they do something different as their peak-to-peak is dT rather than 0.5*dT. Perhaps they start (or have to start) each cycle from zero and to get the correct average frequency they adjust the value of the phase step per dT on different cycles. So in my example of a wavelength of 10.5*dT they would do one cycle of exactly 10*dT and the next cycle of exactly 11*dT.

In rigol specifications there read about jitter:  rms   2ppm+500ps

from 10000000ns period,  2 ppm is 20ns. 20.5ns  rms jitter is lot of.

(of course if they want they can rewrite specifications)

Have you measured what is period time jitter, example over 2-3minutes follow up.
Say example 9.999373 ms or some random other decimals for avoid "golden numbers"
Using Arb and using Square and Pulse.

rms (sdev) alone do not tell much.  (as can see in image 2)

Peak to peak period jitter, in practice in real world.
I need live within peak values, not with rms values when I need timing.
(personally I do not admire this fashion to tell rms values only in specs as we talk pulse generator  time jitter. Who have birth this fashion... )

[jpb]

I did some analysis to work out where the Rigol 500psecs or rms jitter comes from. Here I think that they carry over the surplus phase to the start of the next cycle - what I mean is if the sample step is dT and the wave length of the arb (say a square pulse) is 10.3*dT then it will do 10 samples and start the next cycle with a phase offset of 0.7*dT in the phase accumulator.

The worse case jitter is when the remainder is 0.5*dT so it starts odd cycles with 0.5*dT phase and even cycles with 0 phase so there is a peak-peak jitter (for a vertical edge) of 0.5*dT every odd cycle. This gives an rms jitter of 0.25*dT which 0.25*2nsecs = 500psecs which is what Rigol quote.

From your measurements and Siglent's specifications it looks as if they do something different as their peak-to-peak is dT rather than 0.5*dT. Perhaps they start (or have to start) each cycle from zero and to get the correct average frequency they adjust the value of the phase step per dT on different cycles. So in my example of a wavelength of 10.5*dT they would do one cycle of exactly 10*dT and the next cycle of exactly 11*dT.

In rigol specifications there read about jitter:  rms   2ppm+500ps

Have you measured what is period peak to peak jitter, example over 2-3minutes follow up.
Say example 9.99ms period.
Using Arb and using Square and Pulse.
rms (sdev) alone do not tell much.
Peak to peak, in practice in real world.

I don't have a Rigol, I was merely trying to understand where their specs come from. The 2ppm presumably comes from the 2ppm timebase accuracy. The 500psec I think comes from the way they implement the phase accumulator as analysed above.

My own position is trying to decide on a AWG or AFG hence my interest in the Siglent, the Rigol and various other ones such as the TTi TG5011, a Tabor WW5062 which I could get cheap as it is 7 years old or perhaps an Agilent 33522A from their e-bay store.

As you say, the specs are very difficult to compare, for instance a lot of Rigol's figures are given for 0dBm and it is rather unfair to compare these with Agilent figures which are probably for the full amplitude range to 10Vpp.

What you are doing with the Siglent is very useful as it is giving real measurements, unfortunately without similar measurements from the Rigol say it is still hard to compare.

So to get around this to some extent, I try to analyse what the hardware is intrinsically capable of as a starting point - or rather trying to reverse engineer what the hardware is doing from the specs. So Rigol's specs tell me they don't use a comparator whilst Siglents specs tell me that they do for both pulse and square waves.

[rf-loop]

Here is Rigol DG4000 specs about Jitter (Picture attacment).

I can not read it so that 2ppm come from frequency reference accuracy.

Firsst becouse this affect to all frequencies. Not difference if over or under 5MHz.
2ppm is 2ppm.

But it reads after Jitter(rms)

I think typically in this place we talk about cycle to cycle jitter or period jitter.

So, now I ask: What is time for get value for 2ppm. Is it period time?  If it is period time then for 10ms period it is 20ns. (still not bad for 10ms period - exept we do not know peak values)

If period is 1ms it is 2ns.  In this case 2ns + 500ps is Jitter (rms) 2.5ns and peak-peak unknown.


But then this also:
Agilent 33250A
Signal Characteristics
Squarewave
Jitter (rms)
< 2 MHz 0.01% + 525 ps
? 2 MHz 0.1% + 75 ps

And what are perhaps peak to peak values. (can we name this Agilent as jitter generator)

Last image from Siglent EasyPulse introduction "ad".

[jpb]

Here is Rigol DG4000 specs about Jitter (Picture attacment).

I can not read it so that 2ppm come from frequency reference accuracy.

Firsst becouse this affect to all frequencies. Not difference if over or under 5MHz.
2ppm is 2ppm.

But it reads after Jitter(rms)

I think typically in this place we talk about cycle to cycle jitter or period jitter.

So, now I ask: What is time for get value for 2ppm. Is it period time?  If it is period time then for 10ms period it is 20ns. (still not bad for 10ms period - exept we do not know peak values)

If period is 1ms it is 2ns.  In this case 2ns + 500ps is Jitter (rms) 2.5ns and peak-peak unknown.


But then this also:
Agilent 33250A
Signal Characteristics
Squarewave
Jitter (rms)
< 2 MHz 0.01% + 525 ps
? 2 MHz 0.1% + 75 ps

And what are perhaps peak to peak values. (can we name this Agilent as jitter generator)

That is quite an old Agilent design, though I'd guess it is what Siglent base their design on (in terms of using comparators for square and pulse - I know you don't like me suggesting Siglent do anything other than completely original desings ) which Agilent describe in quite a lot of detail in their manuals.

The Agilent jitter changes with frequency on that model because they change the waveshape used prior to the comparator at that frequency point (Agilent explain things quite well in their manual), they use sine wave above 2MHz and a different shape below (maybe nearer to square wave which then adds some jitter of its own).

With the Rigol I don't know, but at 5MHz 2ppm is only 0.4psecs so maybe they followed the Agilent lead (but without the same reason for it) and argued that above 5MHz the extra jitter would be less than 0.1% of the 500psecs so would be not noticeable. I'm pretty sure that Rigol don't use a comparitor as they have the same jitter specs for square, pulse and arb.

[rf-loop]

Yes, also SDG5000 do not use comparator method for produce Square from sinewave.
SDG1000 use this method, with known cons.

Agilent (destroyed HP), but specially original HP have published lot of details about technology and solutions. This is one reason why I admire (and own many) old HP gears. Full documents, even CLIP manuals. Also example HP journal  have been very nice.
I hope chinese manufaturer read these companies history and publications as lessons how to produce brand and trust. Now they just have started - I hope they learn. Even if equipments are cheap.  I do not know why they all afraid technical details. Copycats - no need afraid.  Perhaps sometimes but this must not be reason to total lack of documentation.  They need learn one thing, Circuits can always copy. But copying example quality - it is more difficult. Do high quality and no one can copy with reasonable price.

We need know, in test and measurement world, all errors and accuracy data - honestly.
If there is maximum peak jitter example 100ns it can write to specifications and not hide it behind some claim that jitter rms is under 200ps.
After people buy equipment and if he have wrong imagine what he buy, you have just made one more disappointed customer whos voice can heard every place in world. 
If buyer know reality, and he accept these before he buy, he is mostly satisfied. 
Chinese manufacturers, do not need shame facts. One unsatisfied customer may shut down 1000 satisfied customers voice. After then, all is loosed.
 Keep one satisfied old customer, it costs one euro. Get new customer may cost 10 euro. Get back loosed customer, it may cost 1000 or it is impossible. 

[jpb]

Yes, also SDG5000 do not use comparator method for produce Square from sinewave.
SDG1000 use this method, with known cons.

I'm a bit puzzled by that, as I thought that was how they were able to get jitter below 100psec vs 500psecs on the Rigol which uses arb for square waves.
Also their specs for square wave duty cycle look very similar to other AFGs that use comparator methods I think.

Agilent use comparators to get squares from sines on their 33250 (80MHz arb) though they change the waveform below 2MHz to get better results at lower frequency.
As you've pointed out the jitter is rather worse below 2MHz. See page 300 of the Agilent manual:

http://cp.literature.agilent.com/litweb/pdf/33250-90002.pdf
 
I know the earlier Siglent model SDG1000 had trouble doing this but they may just have improved the way they do it (e.g. not try and use sines at lower frequencies).

I realise that you've taken it apart so and have done a lot of analysis, so do you know how they generate square waves? They can't use the arb approach as the jitter
is a lot better than they get for arbitrary waves.

[rf-loop]

I know the earlier Siglent model SDG1000 had trouble doing this but they may just have improved the way they do it (e.g. not try and use sines at lower frequencies).

I realise that you've taken it apart so and have done a lot of analysis, so do you know how they generate square waves? They can't use the arb approach as the jitter
is a lot better than they get for arbitrary waves.

My comment was some amount loosy. I mean, they do not use comparator as they have done in SDG1000. This is sure.

9.999999ms period square and peak to peak around 1.5ns jitter where sdev is 66ps. Peak-peak 0.15ppm (0.000015%) and jitter rms <100ps. (0.0067ppm,  period jitter sdev (rms) 0.00000067% )
It do not need any other proofment that this can not do from this period sinewave with simple comparator. If someone can, I want see this world 8'ths miracle.

But, also how they generate now Square, I do not know enough.
It is also possible that with different time period ranges there is some changes how it produce sqr.

Due to many other busy things I have not find time for look deeper.
Of course I'm interest to do it later somehow.
Also there is one undefined IC (only this chip markings removed)  near FPGA and final DAC.
And becouse they have so much advertised this Siglent's  new EasyPulse technology this chip is perhaps related somehow to this?
 

But more than how they do it internally in circuits, I'm interest now how it works for user.  This is now priority.  Accuracy and other things related to signal quality and also some amount of UI. 

It is nice they have added push switch to this round control knob and now can jog between displayed signal parameter settings without need select with separate key..

[rf-loop]

I realise that you've taken it apart so and have done a lot of analysis, so do you know how they generate square waves? They can't use the arb approach as the jitter
is a lot better than they get for arbitrary waves.

Now it is clear.  Siglent SDG5000 produce all waveforms directly by system main DAC.
Including also Square. (I have followed signal with scope  in some different points in signal pathways, with SDG many different settings). This give very low jitter even with very long period time square waves.


What all is this Siglent "EasyPulse" technology doing, I do not know.
Also there can adjust pulse edges rise and fall time wide range (6ns - 6s with 100ps resolution) and same adjust resolution also for pulse width with independent of pulse period time (frequency) (and it do it, but I can not proof how accurate these 100ps steps are)

Main DAC is Analog Devices  AD9781, Dual 14 Bit, 500 MSa/s. (+Dual 10 bit aux dac's)
http://www.analog.com/static/imported-files/data_sheets/AD9780_9781_9783.pdf

DAC output signal go to Intersil EL5166 Current Feedback Amplifier.
http://www.intersil.com/content/dam/Intersil/documents/fn73/fn7365.pdf

Then couple of filters  (and there come some differencies between waveforms) and so on ...level control...
up to final output amplifiers (both channels 4 x Ti 3095)
http://www.ti.com/lit/ds/symlink/ths3095.pdf

Primary ("test") points where I have checked all waveforms.

[rf-loop]

Some tiny Siglent made video.

There is Rigol DG4000 and Siglent SDG5000

It demonstrate somehow what means Siglent  developed  EasyPulse technology, which has been used in SDG5000. I have not Rigol DG4000 so I can not say anything about it. But what all I have tested SDG5082 I can not see any false claim about SDG5000 itself. Rigol case, I can not take a stand.

Rigol looks gorgeous. If want decorate own lab it looks nice and "professional".  But what is inside, what is signal, it is other question.  But in other hand, Rigol have more many kind of features, so it can use also as entertainment machine and just surf and play with it.

One is sure and clear. Rigol DG4000 series do not have anything like what Siglents EasyPulse technology make possible.  Tiny example. 100ms period pulses. Pulse wide example 20ns and around 6ns rise and fall time minimum. Pulse width adjustable up to 100ps resolution and rise and fall time also adjustable up to 100ps resolution from 6ns to 6s (under 6s pulse width is limiting factor. Risetime can not be so slow that pulse top level come clipped) 





More Siglent and example Rigol videos can find here
http://www.soku.com/search_video/q_Siglent
http://www.soku.com/search_video/q_Rigol

(becouse youtube is 97.5% "trash can" (it is pity becouse there is also good valued things under this all trash.)  is blocked in China, there is others like Youku/Soku etc. )

[jpb]

From what you write it appears that Siglent do signal processing of some sort prior to the DAC, in a similar (though presumably simpler as it only applies to square and pulse) way to Agilent's TrueForm architecture. (Agilent digitally low pass filter, interpolate via a filter and then re-decimate for the DAC.)

Looking at the Siglent description :

http://www.siglent.com/en/news/detail.aspx?id=100000041467187&nodecode=119002004

they must detect when sample points fall on an edge and perform accurate edge interpolation (essentially linear interpolation). For short edges they could just do this in memory but since they allow up to 6 seconds with 100 psec resolution they couldn't simply store points in memory. Agilent I think do interpolation using a low pass filter - the sample points are padded out with zeros and then the series of pulses digitally low pass filtered to provide linear interpolation. So it is possible.

[KedasProbe]

The Rigol does have its limitation like shown in the video the min fall/rise is 1/512 of the period.
But the Rigol can generate that very low duty cycle by using the burst mode of 1 cycle.
The higher pulse frequency obviously also limits the max rise time. (min. is 7.0ns)

Example or Rigol below 10Hz (like the video) with a small spike with set fall/rise time:

[rf-loop]

Here near same with SDG5082.
Around same settings.
Pulse adjusted 100ms period, 50ns wide, risetime 30ns, fall time 8ns.
(Owon accuracy for rise/fall measurement is ?)
Acquire mode just normal.

[grego]

I'm looking forward to Dave's review of this thing as it appears to be better than the Rigol DG4000 series - for a fair amount less (e.g. I can get one shipped from China to the US for about $650).  Hopefully Dave gets to it soon as soon as he recovers from the crud he caught.

[rf-loop]

Rise times  and some fall times with all waveforms.


A  100ms period Square
B  100ns  period Square
C  500ns period Ramp with Duty 0.0%
D  500ns period Ramp rise (same dyty as before)
E  100ms period Pulse
F  50ns period Pulse
G  2.5us period Arb (16k) where is 128points high and 16256 points down.
H  500us period Arb (16k) where is build in Stair Down.
J   same as H but one step down zoomed in. (fall time there)
K  same as H but first (full) rising edge.

Jitter have handled before but here one more example mesured now agen but after some selfcal for scope.

M  Pulse 10us period. Picture and measured next rising edge after trigger (period time jitter show 25ps sdev for jitter) (infinite persistence on also for show p-p jitter)

[jpb]

There seems to be an odd asymmetry in some of the waveforms. Particularly noticeable in F and G. The rise time is 6 nsecs as specced from 10% to 90% but above 90% the curve takes a relatively long time to go flat but then drops rapidly at the end of the top flat region.

I don't have enough other comparable curves to compare. The Agilent curves shown here :

https://www.eevblog.com/forum/blog/new-agilent-scopes/645/

are hard to compare because they are thicker and to a smaller scale. They show (different) asymmetry but it is less pronounced.

[rf-loop]

There seems to be an odd asymmetry in some of the waveforms. Particularly noticeable in F and G. The rise time is 6 nsecs as specced from 10% to 90% but above 90% the curve takes a relatively long time to go flat but then drops rapidly at the end of the top flat region.

I don't have enough other comparable curves to compare. The Agilent curves shown here :

https://www.eevblog.com/forum/blog/new-agilent-scopes/645/

are hard to compare because they are thicker and to a smaller scale. They show (different) asymmetry but it is less pronounced.

I do not have comparable test picture from SDG5082.

Later, after I'm back in normal working and have time, I will make some test using same reduced rise and fall speed as Agilent have (specified nominal 8.4ns). After then we can compare agen.

(In Siglent "overshoot" is perhaps reduced too much so that situation is "undershoot" but I think this is, perhaps,  some kind of compromize with some other things)
----------


It is also good to note that Agilent (33522A discontinued model and current B models) are  totally in different price class.
----------

Siglent have 3 year warranty, Agilent only 1 year (why?). Of course there can buy 3 year option from Agilent.  There can also buy ES4 or ES5 option from Siglent (3+1y and 3+2y) and of course calibration services.

[rf-loop]

Here is fast made (holiday visit in workshop) test and adjustments so that somehow comparable with test images here:

https://www.eevblog.com/forum/blog/new-agilent-scopes/645/

Note that this scope is old museum scope and max is 1GSa/s and image is njot as fine as today scopes, but it do still works after 20 years.

Siglent Agilent difference is very clearly seen in 30MHz. I think Agilent is better reject this max frequency under 30MHz.


10MHz  here Siglent rise and fall time adjusted to around same what Agilent can do.
20MHz  here Siglent rise and fall time adjusted to around same what Agilent can do.
30MHz  Siglent
30MHz sample from  Agilent 33522Atested by "Tooms" here  (note  horizontal scale 9.5ns/div)
30MHz (same picture but stretched horizontally so that visually looks nearly same)

[grego]

I just got one of these (SDG5082) and was playing with it for a few minutes last night (had kid issues so didn't get to really poke at it yet). So far it's not bad. The square wave really starts to break down pretty quickly which was disappointing but as I mentioned I didn't get enough time yet to thoroughly test.

I will try to put something together over the coming days. Rf-loop has already been putting this thing through the ringer so I will go through some usage displays and some additional testing.

[jpb]

I just got one of these (SDG5082) and was playing with it for a few minutes last night (had kid issues so didn't get to really poke at it yet). So far it's not bad. The square wave really starts to break down pretty quickly which was disappointing but as I mentioned I didn't get enough time yet to thoroughly test.

I will try to put something together over the coming days. Rf-loop has already been putting this thing through the ringer so I will go through some usage displays and some additional testing.

That would be great. RF-Loop's testing has been pretty thorough but the more different views the better.

Oscilloscopes get a lot of attention whilst function generators much less so. It is hard to much feedback on any of the models.

[jpb]

The square wave really starts to break down pretty quickly which was disappointing but as I mentioned I didn't get enough time yet to thoroughly test.

Can you clarify this a bit? I think all function generators allow square waves up to frequencies well beyond where they look square. For instance the Agilent 33522 with 8.4nsecs rise time will only look square-ish at a period of around 6 times this (to give a bit of flat region) which corresponds to 20MHz whilst square waves are allowed up to 30MHz which is a rather pointy 4 rise times per period.
The Siglent has a rise time of 6 nsecs so things should still look square at around 28MHz but on the higher models they are allowed up to 50MHz.

I guess, since square waves consist of odd harmonics the criteria is the maximum frequency for which the third harmonic is within the pass band of the DACs image reject filter which is set at around 1/3 to  40% of the sample rate. So square wave absolute max is 11 to 13% of the sample rate. Typically though the analogue band width is much less than the image reject filter pass band.

I would say that assuming a Gaussian filter response the flat region is 0.35/rise-time and you want at least the next highest harmonic (the third) to be in the pass-band. On this basis the maximum square-squarewave frequency should be at around 0.12/rise-time which is 20MHz for the Siglent and only about 15MHz for the Agilent but this is probably a bit too conservative.

[rf-loop]

The square wave really starts to break down pretty quickly which was disappointing but as I mentioned I didn't get enough time yet to thoroughly test.

What break down and disappoint?
There is specifications. Max is 30MHz
Risetime  specified <8ns  (and as very common practice 10% to 90% of amplitude)
If risetime is in specs, it means that one cycle (10%-90%) risetimes take <16ns  and with 30MHz whole period time is 33.3ns.  Now there is left 7.65ns for both, bottom and top of square. Including these four corners 0%-10%, 90%-100%, 100%-90% and 10%-0%.  How much there is then time for "flat" bottom and top.  These corners are some amount soft but in practice where exactly it is problem exept in human eye?
It is compromise of many things. And it meets it specifications well even with these max limits settings.
 (perhaps these corners shape can quite easy get more sharp with this same rise and fall times but good question is - why,  and what are possible bad side effects)
 
If need more fast risetimes than specified <8ns then it need buy different equipment.

[rf-loop]

There is now new FW  (not yet available in Siglent public Download center)

More tests is coming soon after I  first look this new FW and if it change something in signal. This is signal generator so signal is most important thing in my scale of priority.

[grego]

Hey loop - do you think I could get ahold of that new firmware since it's not yet on the site?

[rf-loop]

Hey loop - do you think I could get ahold of that new firmware since it's not yet on the site?

I do not recommend. 5.01.01.08 have problem.
I have not yest tested if can go older version back. (perhaps not)

[grego]

Good to know.  Thanks.

I'm goign to be doing a use review on Youtube hopefully later today, at worst on Friday, of the 5082.

[rf-loop]

Good to know.  Thanks.

I'm goign to be doing a use review on Youtube hopefully later today, at worst on Friday, of the 5082.

Now I know that it can downgrade back to 7R1. (so it is good to keep also available if need)

I will look later more about this version 8 propable problem, after I have time for look it more.

[grego]

So I wanted to just throw a couple of screenshots up - I got my Agilent 6012 this afternoon and immediately hooked it up to the Siglent SDG5082 with a 50ohm feedthrough term (Siglent set to 50ohm out).  Rise time on the square wave is fantastic at under 7ns.  Also very little overshoot, coming in at around 0.8% on average.  Frequency is also pretty reasonable even at 80Mhz coming in with a standard deviation of around 200kHz (or about 0.25% of 80Mhz target).

More coming later.  If you're curious, yes the 6012 has a valid calibration at this time.

[rf-loop]

Frequency is also pretty reasonable even at 80Mhz coming in with a standard deviation of around 200kHz (or about 0.25% of 80Mhz target).

Do you really mean that 80MHz sinewave from SDG have 200kHz sdev. 
You have FM modulation on?

Which one now pull, horse or wagon.

So you have classified your oscilloscope and get information that oscilloscope measurement  have total lack of accuracy for this measurement (in this case 80MHz sinewave frequency stability)

Simply, with SDG you can test how much error this oscilloscope produce in this measurement.
200kHz sdev is so much that if you get this result with equipment what data really can trust in this measurement with enough accuracy you can immediately send your Siglent SDG back and tell it is failed, totally out of order.  it was sdev, and also, if it is peak to peak error it is so much that if signal generator p-p error for 80MHz sinewave is 200kHz it is just total garbage. Very bad made 80MHz simple LC oscillator is far better.

Instruments what give lot of data are nice but also it is good to  understand when they are not valid, decimal point is totally wrong place for this. (exept if want know this oscilloscope mesurement quality in this case)

[grego]

No, modulation was not on - devices had been warmed up for about 30 minutes and were humming along just fine.  I let the sine run for a bit, reset the stats on the scope and then let it acquire another set of points before taking the screenshot.

Please note - I did say my scope was a 6012 - e.g. a 100Mhz scope - so I was well past what I should be from a bandwidth perspective.  To truly test I'd use at least the 300Mhz version, which I don't have.  The measurements are completely valid - as long as you take into account the comments made.  I was not hiding anything and was quite upfront about the equipment I am using.

I'd hold off on bashing an Agilent MSO6000 with a valid calibration.  You do, however, have to take bandwidth into consideration.

rf-loop, you do great work here - I've really enjoyed your deep dive into the 5082 (hell, its one of the reasons I decided to risk buying one here in the states since I can't easily get it repaired, warranty or otherwise), but you get really antagonistic sometimes.  Relax.

[grego]

Separately I'll be posting a brief overview video on Youtube on this thing shortly.  Nothing special, just run through the basics.  Video work could be better but meh, it's an overview.

[rf-loop]

rf-loop, you do great work here - I've really enjoyed your deep dive into the 5082 (hell, its one of the reasons I decided to risk buying one here in the states since I can't easily get it repaired, warranty or otherwise), but you get really antagonistic sometimes.  Relax.

In this test image with scope there read
Freq current 80.3MHz
Freq mean 80.001MHz
Freq min 79.4MHz.
Freq max 80.6MHz
Std Dev 197.59kHz   

Then you tell:

  Frequency is also pretty reasonable even at 80Mhz coming in with a standard deviation of around 200kHz (or about 0.25% of 80Mhz target).

If signal have this max and min and this sdev (in freq) it is so total crap signal generator or better say it have some kind of failure. (but of course it is not)

I can not be without comment it or better say shoot it down. Becouse this is not my natural language I do not know how to write so that my words have still nice flowers. This is NOT at all any personal or any kind of angry or something like this.

But I need tell that this data do not tell about SDG5082 signal quality and there is not 200kHz sdev and not 1.2MHz max - min  freq error. It only tell that this oscilloscope measurement accuracy is not at all enough for test this sinewave frequency stability. It need  least 5 decade more resolution/accuracy.

Btw, one quik test what tell also easy something  about signal. If have good quality HF receiver. Take out some HF carrier, example 28.xx MHz.  Then, turn SSB on. Tune example 1kHz off. There need hear quite clean 1kHz audio. It can give some kind of mutual imagine about signal quality (or radio quality if it is not enough high)
 
Also if there is available special good quality sinewave and then ordinary mixer and then this device under test signal.

Take out exmple 80MHz from SDG and 80 001 000.00 Hz from this very good source. Now there can look this mixer output 1000Hz. and look how is its stability. Or it can mix more close... example to 100Hz.  Of course output have now both signals errors, so this external signal need be as good as possible.

I add note (for avoid more misunderstoodings): This answer and earlier answer is writed with  kind mind and it is very nice to see these test images. It is also useful becouse it clearly show what kind of limits there is or may be even with very good instruments - but if try measure things what they can not do.

Also it show that not only  SDG5082 what I have tested  have this risetime and  same shape of square wave. More data, more we know it is not only single individual unit.

[rf-loop]

Separately I'll be posting a brief overview video on Youtube on this thing shortly.  Nothing special, just run through the basics.  Video work could be better but meh, it's an overview.

Please do you have link for this? (I can not find it in youtube)

[grego]

Separately I'll be posting a brief overview video on Youtube on this thing shortly.  Nothing special, just run through the basics.  Video work could be better but meh, it's an overview.

Please do you have link for this? (I can not find it in youtube)

It'll be up shortly - it's just a use overview with a little bit of a dive into the square wave jitter, rise-time, etc.  Nothing major.  Waiting for youtube to do its thing then I'll post.  I even give you a shout out in it.

[grego]

BTW rf-loop - I need to run a couple more tests but I am beginning to think there's something wrong with the scope.  I've now checked at various frequencies on just a sine wave through my freq counter and the std dev is about (@35Mhz that I just tried) 0.162Hz.  On the Agilent it was 90kHz.  So something is up.  I was min/maxing on the Agilent (again @35Mhz) 34.7Mhz/35.1Mhz as I recall -- which doesn't jive with the freq counter.

I'm going to hook up another scope tomorrow and doublecheck but it looks like something is wonky in the scope.  All the other scope measurements are solid, but frequency seems to be off.

[rf-loop]

BTW rf-loop - I need to run a couple more tests but I am beginning to think there's something wrong with the scope.  I've now checked at various frequencies on just a sine wave through my freq counter and the std dev is about (@35Mhz that I just tried) 0.162Hz.  On the Agilent it was 90kHz.  So something is up.  I was min/maxing on the Agilent (again @35Mhz) 34.7Mhz/35.1Mhz as I recall -- which doesn't jive with the freq counter.

I'm going to hook up another scope tomorrow and doublecheck but it looks like something is wonky in the scope.  All the other scope measurements are solid, but frequency seems to be off.

 In measurement it need know what time it exactly cross levels beginning and ending of "cycle".  If oscilloscope is "ideal" machine without  noise and if it use direct sampled data, what is resolution. For easy thinking take example 50MHz. Its cycle time is 20ns.

In this cycle time, if there is 2GSa/s sampling speed (as in this case is) there is 40 samples for 50MHz. How accurate it can now tell how long is this cycle.  If there is 41 samples in some cycle. It is now 20.5ns = 48.78MHz
Of course now it may do something more. It may interpolate between true sampled points and estimate time when it cross same level what it use for start of mesured cycle.  It may give small amount better result. But of course this simple example is enough for tell that resolution/accuracy is far far  away from what need for characterize this sinewave fidelity in frequency/time.

I think your oscilloscope is working just ok. But it is wrong tool for just this. But good/very good for many other things.

How if look resolution for 50kHz instead of 50MHz. 50MHz we get 40 sample points 1/40 of cycle, but 50kHz 40000 sample points etc.

Your measurement with freq counter, result is ok and not conflict with my measurements, but now, there is also problem dependent of freq counter (time interval counter). It use still many many cycles (depends gate time) for one freq result so it is "average". Then agen, many many cycles for next freq result what is agen average. Then it do statistics with these individual results and give average, min, max, sdev etc...
But every sample in this calculation is average.

What is wrong here. Nothing or much of. It depends what we want exatly really know.
If we want know every single sequential cycle frequency and result what is min, max and sdev etc...  well we are troubles how to do it. Directly with time interval counter? I do not know time interval counter what can do it for example 50MHz or just this 80MHz.  I have very poor counter HP/Agilent 53131A (good but poor for just this). Its time interval resolution is 500ps. (so just nothing for this)  If it have 50ps... still nothing... 5ps... nothing, how about 500fs or 50fs. And even if enough resolution, can it timestamp every single sequential cycles, or if can not then example every tenth or hudreds cycle.. or random but enough fast... then collect 10000 these and calculate.  I like to have this machine.

But then, if we have enough good quality signal available... we can use mixer for convert down this freq what we are testing. If there is available "ideal" signal exactly 10 000 0100Hz and then signal under test is "10MHz. After mix there is  clean 100Hz signal (if 10MHz under test is perfect). It have now these errors what this 10MHz signal under test have. (if 10.0001Hz signal is "ideal") If 10MHz signal under test jumps 1Hz our 100Hz signal jumps 1Hz. Not difficult to detect.  Now there is 100Hz stream where we need detect all time errors.

[grego]

Video overview is up:

[rf-loop]

I have made some more tests with spectrum analyzer.

Here in these pictures signal from SDG5082 is of course sinewave. Level is in all pictures 0dBm and naturally 50ohm. Signal go around 2.5m in coaxial to HP8568B spectrum input. (some amount crap cable but no matter in this test)
Note about spectrum analyzer. Freq related some calibrations are not perfect but in this case this do not mean "anything" just "cosmetics" in numbers.

I have used 10Hz RBW and 100Hz RBW.
In some image signal is 20dB over top reference line! (note this as you think trace levels - as told signal is always 0dBm level)

Note for this displayed traces. In all pictures mode have been MAX hold. So this level is more like peak noise level than avarage noise level!

Many times in specs is use average noise levels or displayed average noise levels or something like it. With human eye it may somehow imagine where is average.

Then, most specs today give  dBc/Hz
Oh well, it is nice but it is not what you see.

How to convert displayed noise level for dBc/Hz.
Ok, example. If carrier (this c) is level 0dBm  and then  example 1kHz we can see trace level is
-50dBm. We can say its level is -50dBc (dB related to carrier level) Then RBW (resolution bandwidth) is 100Hz.  It is 100 times more wide than 1Hz RBW. Ok, it is 20dB.  So this -50dBc with 100Hz filter responds -70dBc/Hz  (70dB below carrier if RBW is 1Hz)
Why I use 100Hz RBW is just becouse my timetable was busy and narrrow RBW sweep takes forever.


Image A


80MHz  carrier is just left and there is 1kHz span  and  10Hz RBW
Reference level is same as signal (0dBm)
note  for dBc/Hz -10dB due to 10Hz RBW
(if you think reference level is -10dB this give right level for dBc/Hz)



Image B


10MHz  carrier is just left and there is 1kHz span  and  10Hz RBW
Reference level is same as signal (0dBm)
note  for dBc/Hz -10dB due to 10Hz RBW
(if you think reference level is -10dB this give right level for dBc/Hz)



Image C


1MHz  carrier is just left and there is 20kHz span  and  100Hz RBW
Reference level is -20dB under carrier level.
note  for dBc/Hz -20dB due to 100Hz RBW
(if you think reference level is -40dB this give right level for dBc/Hz)



Image D


50MHz  carrier is just left and there is 200kHz span  and  100Hz RBW
Reference level is -20dB under carrier level.
note  for dBc/Hz -20dB due to 100Hz RBW
(if you think reference level is -40dB this give right level for dBc/Hz)

[rf-loop]

These previous tests with spectrum analyzer are not real phase noise measurements - of course.
So, need be careful when doing  conclusions.

Siglent specifications (service manual, undefined version but 2013 - and also in other documents):

Phase noise 100kHz Offset, –116dBc / Hz (typical value)

Image D show 50MHz carrier and 200kHz USB.
100kHz from carrier, trace is between -100 and -110dBc/Hz (displayed between -80 - 90dBc with 100Hz RBW). But now, it need tightly remember what I told before = HP spectrum MAX HOLD  was used so from this trace can not estimate signal average noise level.


Image C shof 1MHz carrier and 20kHz USB.
10kHz from carrier, trace is between -110 and -120dBc/Hz (displayed between -90 and -100dBc/100Hz)

Images A and B show 1kHz USB from 80MHz and 10MHz carrier.
If look both traces curve and compare these example between 100 to 200Hz from carrier.
Image A (80MHz) display trace is nearly between -40 and -50dBc
Image B (10MHz) display trace is nearly between -57 and -67dBc
(10Hz RBW so subtract 10dB if want think dBc/Hz)

With this measurement, I think there is not markable conflict with specifications.
But I hope Siglent (and others) give more detailed specifications.
What it tell to customer if write "Phase noise 100kHz Offset, –116dBc / Hz (typical value)"
what is typical value meaning. How much variations typically. What is "typical" frequency. 1MHz? 33MHz? 157MHz? or what?
What are quaranteed values for different frequencies.

Personally I do not like at all  these "typical" values what means that manufacturer is not responsible if this given value is right or wrong.

[rf-loop]

Here some amount better phasenoise measurements.
EDIT: later I do tests agen. There is some problem in my measurements.
It looks like results are better and partially far better than now measured.
Before I have new data I keep this picture as "worst case" until other data owerwrite it.


(other thing is area below -110dBc between 10kHz - 100kHz)


Used equipment HP-8568B
Becouse some small freq inaccuracies, for every scan I have first looked what HP cursor show about frequency using 30Hz RBW and then used it in well knownKE5FX software.
In all measurements SDG output so that HP see it as -10dBm
Last two traces are just for reference, measured without any signal.

All phasenoises are
< -100dBc/Hz offset 20kHz
< -120dBc/Hz offset 200kHz

In Siglent specifications only given value is:
100kHz Offset, –116dBc / Hz (typical value) 
(what means typical?)
in my measurement between -112 and -115dBc/Hz  offset 100kHz

It need note that this old HP8568B calibration certificate is expired long ago.


80MHz
40MHz
20MHz
10MHz
5MHz
1MHz
1MHz no signal
80MHz no signal


test work error, image removed

This measurement have undefined error! Phase noise  values may be much better.

Also note: In this measurement, with these settings,  HP limit can think if you draw around -113dBc level horizontal line from 1kHz to around 90kHz. Then slope down and somewhere around -130dBc or some amount better.  100Hz have limit around -100dBc.  Traces without signal show only base noise level with this setting! They are not bottom base levels for phasenoise. (and together with correction factor in PNB software.) 

[jpb]

Here some amount better phasenoise measurements.
Used equipment HP-8568B
Becouse some small freq inaccuracies, for every scan I have first looked what HP cursor show about frequency using 30Hz RBW and then used it in well knownKE5FX software.
In all measurements SDG output so that HP see it as -10dBm
Last two traces are just for reference, measured without any signal.

Thank you for those. The specs give -116dBc/Hz at 100kHz as a typical value which is in agreement with your measurements for the 10MHz curve (Rigol state their specs at 10MHz while Siglent don't give a specific frequency but I guess that 10MHz is reasonable).

I'm no expert, but the values below 10kHz offset seem quite high (comparing with Agilent and Tabor specs which again are "typical" but do give several values rather than just one point).

Presumably if a good external reference is used the phase noise is reduced? (Someone on these forums did some measurements on the Rigol DG4062 with and without an external reference).

[rf-loop]

Here some amount better phasenoise measurements.
Used equipment HP-8568B
Becouse some small freq inaccuracies, for every scan I have first looked what HP cursor show about frequency using 30Hz RBW and then used it in well knownKE5FX software.
In all measurements SDG output so that HP see it as -10dBm
Last two traces are just for reference, measured without any signal.

Thank you for those. The specs give -116dBc/Hz at 100kHz as a typical value which is in agreement with your measurements for the 10MHz curve (Rigol state their specs at 10MHz while Siglent don't give a specific frequency but I guess that 10MHz is reasonable).

I'm no expert, but the values below 10kHz offset seem quite high (comparing with Agilent and Tabor specs which again are "typical" but do give several values rather than just one point).

Presumably if a good external reference is used the phase noise is reduced? (Someone on these forums did some measurements on the Rigol DG4062 with and without an external reference).

It need note that this my measurement with HP8568B give perhaps too bad results.
I have compared same measurements using my HP8644B for signal, and example HP53131A Option 010 Owen 10MHz  output (what is typically very good) and results are so that I need suspect this HP8568B give too bad results specially between 10kHz to 200kHz under 100dBc levels.
(specially test with HP8644B give sign that something is wrong under 100-110dBc and specially offset > 10kHz.)

Add, now also looked something using HP8901B and 5386A and this whole phasenoise test can read as garbage. I do not know yet what is wrong but it is sure, it is not SDG phasenoise.
It is difficult to compare equipments data sheets becouse specs are so different and ambiguous.

Rigol DG4000  60MHz model around USD 900
Typical (0 dBm, 10 kHz deviation)
10 MHz: ?-115 dBc/Hz

Agilent 33250A (used somehow trusted condition around USD 3000
Phase noise (30 kHz band)
10 MHz <-65 dBc (typical)      (Siglent SDG5082 around  <62dBc)
80 MHz <-47 dBc (typical)      (Siglent SDG5082 around  <44dBc)

Agilent 33500B (max 30MHz)  Around USD 3300
Phase noise (SSB) (typ) (what frequency?)
1 kHz offset: -105 dBc/Hz
10 kHz offset: -115 dBc/Hz
100 kHz offset: -125 dBc/Hz

Tabor WS-8102    Saelig price USD 5400  eBay USD 4500
SSB Phase noise (10kHz offset)
1MHz <-115 dBc
10MHz <-100 dBc
100MHz <80 dBc

Siglent SDG1000 series (25MHz < USD 400)
Phase noise 10kHz Offset? –108 dBc/Hz (typical value) (What frequency?)

Siglent SDG5000 series (80MHz in eBay around USD 700)
Phase noise 100kHz Offset, –116dBc/Hz (typical value)(What frequency?)

[jpb]

Yes, it is difficult to compare data sheets as they (deliberately?) give their numbers under different conditions.

The Tabor I was looking at is the WW5061/2 as I can get that at a low price. The figures for that are for an 8 point sine wave at maximum clock which I calculate as 6.25MHz (50/8):
100Hz <-103dBc/Hz
1kHz <-110dBc/Hz
10kHz <-118dBc/Hz
100kHz <-124dBc/Hz
1MHz <-135dBc/Hz

The list price for the WW5061/2 is very high but it has been around a long time and is available at a discount. Unfortunately it has a maximum sample rate of only 50MS/s (limited by firmware - the hardware is capable of 125MS/s).

[rf-loop]

My last phase noise measurement with spectrum analyzer have bad error!
I do not yet know what is wrong but when I "listen" SDG using HP 3586A and HP 8901B it give sign that  phase noise from SDG can not be this level specially between measured 100Hz - 10kHz USB.  Error is not "cosmetic" -  can not say now more than "error is big"

[rf-loop]

This test annul the previous phase noise tests in this context what I have made.

SDG5082  phase noise measured using HP8568B spectrum analyzer and KE5FX phasenoise tool.
SDG signal (Ch1) 0dBm, 80, 40, 20, 10 and 1MHz,
Spectrum analyzer input attenuator 10dB
Clip level 20dB (in KE5FX phasenoise tool)

Dark blue line is made with exactly same settings and levels using Agilent 8644B signal generator.
Output level 0dBm, freq 10MHz. Line is hand draw as accurate as reasonable. This is only as bottom  limit reference line and valid only with this individual spectrum analyzer.
Note for 1MHz carrier. Range is 200Hz to 1MHz. Near 1MHz offset carrier 2nd harmonic visible and that is why red 1MHz curve jump up there due to quite wide RBW used near 1MHz offset.



Note: spectrum analyzer limit around -115dBc


In attachment image:
HP3114 function generator.
10MHz sine, level 0dBm
just for fun.

[rf-loop]

Some "finding".

If CH1 and CH2 is on and then shut off SDG. (start with last setting selected)

It turns on and settings are same but...

If there was selected dBm for channels level it change to display voltages peak to peak.
(same level still of course)  I like more if it keep also level display units what I have selected before.
Now how I return to display dBm if I do not want change level and I do not exactly remember last dBm value.

There need be feature to change displayed units without change settings. If I have selected dBm example 0dBm, how I can change it display volts.
I hope they add this in later FW.


If power up, of course it powers up with channels off,  but internally it still produce this waveform what was selected. Internally it continue generating still this waveform with previous settings.
If now measure output there is still some (but very low level) leakage to output.

If now turn channel on (of course now selected signal come out with selected level)
and  then shut  channel off it stops whole channel and now if measure this channel output, there is not at all this small level leakage.

If do some very sensitive works it need take care that really shut off not used channel and not only output relay.

If shut off when channel is really totally shutted off and then power up, it is shutted off totally.

If shut off when channel is on. Then power up. Only output  is shut off but still channel signal on internally.

In sensitive works it may also affect due to small leakage from channel to channel internally.

I hope they change this in FW. Always if channel output light is off this channel need be totally off and not only output off also after power up after channels have been on when power shutted off.




 

[happyday]

I have test the result that at 50ohm,0dbm and 1KHz square wave

with my SDS1102CM, and I found it's Vpp=896.0mV
I think maybe you check whether it is correct

[rf-loop]

I have test the result that at 50ohm,0dbm and 1KHz square wave

with my SDS1102CM, and I found it's Vpp=896.0mV
I think maybe you check whether it is correct

And your oscilloscope have 50 ohm input impedance? 

[rf-loop]

SDG5082   
Output 50ohm, 1kHz Square 50%  duty, DC offset 0, level 0dBm.

Result with oscilloscope:
HP54522A 50ohm input:

Vampt 450.74 mV
Vp-p 458.38 mV

Average 1024:
Vacrms 225.31 mV
Vdcrms 225.31 mV

Note: specifications about Oscilloscope and SDG level and input/output  impedance accuracy!



SDG5082  result with power meter: HP437B + HP8482H sensor

Output, 50ohm, 10MHz Square 50% duty, DC offset 0V, Level 0dBm
Result: -0.31dBm

Same but 1MHz Square
Result: 0.08dBm

10MHz Sine, DC offset 0, Level 0dBm
Result: 0.02dBm

Same but 1MHz Sine
Result: 0.08

[Siglent]

The firmware of SDG5000 has updated to 5.01.01.10
and the firmware of SDG1000 has updated to 1.01.01.31
you can download them from our website.
http://www.siglent.com/en/server/download.aspx?nodecode=119004002006

[grego]

The firmware of SDG5000 has updated to 5.01.01.10
and the firmware of SDG1000 has updated to 1.01.01.31
you can download them from our website.
http://www.siglent.com/en/server/download.aspx?nodecode=119004002006

Some release notes would have been nice.  Whats changed?  What's fixed?  What's different?

[grego]

Hey Siglent - are there any release notes for this new firmware?  I don't know anyone who likes to blindly install firmware on their gear without an inkling of what the changes are.

[Siri]

rf-loop, Siglent,

Does SDG5082/5162 blending mode (summation) of the signals from the two channels?

For example, if required to form one channel AM-modulated signal on the shortwave band simultaneously with a certain pulse signal (noise)?

[Henrym3]

I am considering using it with a 5mhz ULTRASONIC TRANSDUCER .... do you think it is possible ?

Infact, I was wondering if I can make a transducer like this http://www.amazon.co.uk/Generic-Intelligent-Ultrasonic-Thickness-1-2~225mm/dp/B00EQ1X6N2 (it uses 50mA) , working with my SDG5082 ?

What do you think ?

[Siglent]

rf-loop, Siglent,

Does SDG5082/5162 blending mode (summation) of the signals from the two channels?

For example, if required to form one channel AM-modulated signal on the shortwave band simultaneously with a certain pulse signal (noise)?

You can use the Easywave software to accomplish  this function.
In the "Math--Arithmetic Math--Two wave math" menu, you can synthesis two waveform into one waveform by addition/subtraction/multiplication operation. And then send the waveform data file to SDG5000 generator to output it.
For the waveform which have already stored in the generator(5 standard waveform, 46 types built-in function waveform and 10 custom waveform), you can send to Easywave and operate them directly. For the others waveform, you need edit the waveform by yourself.

[Siri]

Thank you, Siglent.
EasyWave created and sent in generator a complex signal may change slightly in the future in terms of the parameters (frequency carrier, noise pulses period, etc.) without a computer operatively in the generator?

[rockandroll]

@Siri
Do you mean blending mode(summation) like Siri asked ?

I am considering using it with a 5mhz ULTRASONIC TRANSDUCER .... do you think it is possible ?

Infact, I was wondering if I can make a transducer like this http://www.amazon.co.uk/Generic-Intelligent-Ultrasonic-Thickness-1-2~225mm/dp/B00EQ1X6N2 (it uses 50mA) , working with my SDG5082 ?

What do you think ?

[Henrym3]

No, I was just interested in driving 2 ULTRASONIC transducers, using my SDG5082.

Did any of you have any experience using it with ultrasonic ?
Do you think is possible (or the SDG5082 mA power is not enough) ?

[Farrari]

No, I was just interested in driving 2 ULTRASONIC transducers, using my SDG5082.

Did any of you have any experience using it with ultrasonic ?
Do you think is possible (or the SDG5082 mA power is not enough) ?

how about the impedance ?

[Siri]

Acquired SDG5162 and faced with the fact that the generator is very dirty spectrum of a sinusoidal signal 
Pictures from rf-loop at the beginning of the theme just exemplary in comparison with the spectrum SDG5162!





Occurs parasitic frequency modulation signal. Modulation frequency and the deviation increases with programmable frequency sinusoidal signal at the output.

[Siri]

Continuing study SDG5162, found an error in adjusting the output level.
If you use the dBm-scale output, the setup level since -40 dBm and below an error, the actual output level at 1 dB less than the set:

Setting  /  Out.
...
-38 dBm / -38 dBm (OK)
-39 dBm / -39 dBm (OK)
-40 dBm / -41 dBm
-41 dBm / -42 dBm
...

Update:
More precisely, an error occurs when switching between -39.6 dBm and -39.7 dBm
(at this point inside the generator relay switch clicks next level range)

[Farrari]

Your image can not be displayed

[Siri]

Strangely. I checked with several computers, pictures visible.
Maybe your provider blocks somehow photo service from russian Yandex (?)

[Henrym3]

The transducer cable impedance  is 50 ohms.

Will it work ?

No, I was just interested in driving 2 ULTRASONIC transducers, using my SDG5082.

Did any of you have any experience using it with ultrasonic ?
Do you think is possible (or the SDG5082 mA power is not enough) ?

how about the impedance ?

[Herman]

according to the datasheet of SDG5000,CH1/CH2<40MHz: 1mVpp~10Vpp(50 ohms),
when the impedance is 50 ohms,
Vrms=10V/(2*1.414)=3.54V,
current=3.54V/50ohms=0.0708A=70.08mA,
so the max output current is 70.08mA.may it help

[Henrym3]

Thank you Herman , very useful !

So based on your calculation, I should feed them with 2.5 Vrms each, to get the required 50mA power to drive them. Correct ?

according to the datasheet of SDG5000,CH1/CH2<40MHz: 1mVpp~10Vpp(50 ohms),
when the impedance is 50 ohms,
Vrms=10V/(2*1.414)=3.54V,
current=3.54V/50ohms=0.0708A=70.08mA,
so the max output current is 70.08mA.may it help

[Herman]

yes, and your Ultrasonic Thickness Meter Power supply:3 x 1.5 AAA Alkaline Batteries(not Included) ,why don't you use  DC output.

[Siri]

Siglent,

What can you say about a dirty sine wave. It is normal for SDG5xxx or my device is defective?

[Herman]

Siri
This is the test result with my Agilent 8596E which is old, and the spurious signal data of SDG5000.


By the way ,how about your frequency modulation signal setup?(FM frequency,FM dev)

[Siri]

Herman
When watching spectrum of the generator, modulation was off course.
Try to look more high-frequency signals (25, 50MHz and above).
Operating frequency of 10 MHz is not very revealing. While here, you can see that the declared parameter -116 dBc fails.

Siglent,for what frequency spacing specified in the characteristics "-116dBc/Hz low phase noise (SSB) signal output"?

Find more here
http://www.siglent.com/UploadFiles/en/Files/DataSheet/SDG5000_DataSheet_en.pdf
"100 kHz Offset,-116dBc/Hz (typical value)"
Anyway, in the band 100 kHz nothing like this.

Update.
Sorry. Spacing at 100 kHz noise -116dBc/Hz really turns out to stretch. But on a smaller distance from the center frequency of the signal is very dirty and call it a "low noise" does not. And the more the set frequency, the worse.

1MHz sine wave



5MHz sine wave



25MHz sine wave



50MHz sine wave

[rf-loop]

Perhaps you have allready carefully readed these some tiny tests:
https://www.eevblog.com/forum/testgear/tests-siglent-sdg5082-waveform-generator/msg273815/#msg273815

Note that even HP8568B (and it is quite good (traditional spectrum) for this) can not measure phase noise enough down specially between 10k to 100k from cf.  (look reference line made by HP8644B what is not so bad signal gen)
(note: these kind of methods do not really measure phase noise! )

[Siri]

rf-loop
Thanks for the link and your work.
Oh, to see the "tails" with the level of -20 ..-40dB does not need much effort or special equipment or techniques.

Here is an example of another generator, which is considered an average purity of the output signal:

1MHz



5MHz



25MHz



You see difference with the pictures of SDG5162 above..

[Siri]

I asked the local seller to see other instances SDG5162 mode sinusoidal signal. I do not have a defective version, all 5162 the same pattern with the noises in the nearest band.. So this question to a member Siglent is removed. But it seems to me, he's not soon reply to this topic

[rf-loop]

Note for signal amplitude when using AM modulation.
For avoid confusion this is good to know and understand how this works and what it means in practice.
This is how it is made and how it works. Also may help SDG1000 series users.

When you turn MOD (AM) on, independent of modulation depth (0 - 120%) signal carrier level drops to half of what is indicated on the screen level.  If Modulation depth is now 0% you just see that signal level is half from displayed level value and there is only carrier alone. No sidebands.

There are perhaps many peoples who are not so familiar with dBm, dB, dBc so I use also voltage in example.
Also this equipment dBm is only usable if system impedance is 50 ohm.

In start point lets think you set sinewave, say example 1MHz and level 1Vpp, impedance 50 ohm and MODulation function is OFF.  Offset level 0V.

Your load is 50 ohm.  This sinewave  is now 1Vpp (+0.5Vpk and -0.5Vpk)
(if your load is not 50 ohm - if load is very high impedance you get double voltage level)
You can look it with oscilloscope (50 ohm input) and it is nice sinewave 1Vpp (0.5Vpk)    If you look with Spectrum analyzer you can see around 4dBm peak.

Now, push MOD and select Modulation ON, set modulation example 1kHz and depth 0% (no modulation)
Just when you turn modulation on and % is 0 your signal (carrier) level is now  500mVpp.
Also look oscilloscope and it is true, nice unmodulated sinewave 500mVp-p (0.25Vpk.  If you look with Spectrum analyzer you can see around -2dBm peak. (as you see it drop 6dB from start)

What happen when you use other than 0% modulation depth. Let's try. Set 100%.
Now if you look this with oscilloscope. You can see 1kHz sinewave modulated carrier (if your scope is now example 2ms/div speed)  where minimum is zero level and maximum is 1Vp-p --- yes it is right. (also this max is now same what we have before we turn MOD function on!  So, modulation envelope peaks max are now same as your original level set.

Now if we look this with spectrum analyzer. What.....  carrier is still this same -2dBm level
(and if we can look with oscilloscope just alone this carrier (we can not easy do it) its is.....    500mV peak to peak continuous sinewave.)
What other we see with spectrum now. We see two peaks, 1kHz down and 1kHz up from this carrier.
We see three peaks. Center peak is carrier, level -2dBm and then we see upper and lower side peaks but level of these peaks are 6dB below carrier level. In this case -8dBm.

What now if you half this modulation depth. Set 50% depth.
If you are now  looking  with spectrum carrier do not change at all.   But if you look this signal normally with scope and this modulation envelope. Then peak to peak max value is not anymore 1V. But also it do not go anymore to zero.
With spectrum analyzer there is still -2dBm carrier and then both sideband peaks are now dropped 6dB more. They are now both -14dBm. (and if you now drop modulation again half, 25%... carrier stay same, sidebands drop again 6dB and they are now -20dBm level (-12dBc   (-12dB from carrier level)). And now with scope this modulated signal envelope peaks less.

Remember.
When you turn Modulation function AM  on, your signal level is half if it is only carrier (mod depth 0%).
So, if you want your carrier is 1Vpp then set sinewave level 2Vpp.
But now remember also that when modulation depth is more your signal peaks are more than 1Vpp. And with 100% MOD it is 2V peak to peak.

I do not say this is good or bad, right or wrong,  they have made it like this. Least one positive thing there still is. You can not easy make damage if you set signal level and then turn mod on and 100%. It do not exceed what you have set.

Most of real RF generators works different. There if you select signal level example +3dBm and then you turn modulation on, your carrier is still +3dBm and what ever modulation depth you select or turn MOD off... your carrier stay rock solid +3dBm.  (RF world it is very common to use power level dBm and usually in 50 ohm system.


Siglent Function generator SDG5000 is not any kind of exception. There is many kind of variations how different manufacturers have done these.

Before serious use: "Know your equipment features"

There is not enough information in user manual or data sheet about  this kind of things and details and this lack of information is not nice - even when  peoples do not today deep study manuals. ("why read manual if there is only trivial things and nearly total lack of important details" )

Here starting from this message there is some messages and images what may explain more this equipment behavior.
https://www.eevblog.com/forum/testgear/siglent-sdg1025-arbitraryfunction-generator-under-some-tests/msg1160671/#msg1160671


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

And this is why:  RTFM

SDG models manuals tell it exactly:
* In the 0% modulation, the output amplitude is the half of the set one. 
* In the 100? modulation, the output amplitude is the same with the set one.

(exept that in some models some manual version may tell wrong that 120% mod amplitude is same with set one. This is error, there need read 100%)