Power Supply parameters - Output Noise
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- čas přidán 31. 03. 2023
- #186 In this video I look at the noise that is present on the output of a power supply and the various reasons for it being there. The noise level is of course dependent on power supply type - switching converters are usually more noisy than linear regulators, but you also need to factor in the noise already present on the input side, and finally the exact way in which the circuit is built will have an impact on the output.
PSU Series videos
PSU Static Output: • Power supply parameter...
PSU Dynamic Output: • Power Supply parameter...
PSU Output Noise: • Power Supply parameter...
Related videos:
LNA Ep1: • Electronics Tutorial -...
LNA Ep2: • Electronics Tutorial -...
LNA Ep3: • Electronics Tutorial -...
Further reading:
www.ti.com/lit/an/slaa414a/sl...
www.ti.com/lit/ds/symlink/lm3...
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"because of the chunky way in which energy is transfered through the circuit"
A+ phrasing, I'm gonna use that
you are not FesZ, you are GreatScott!!
Nice please make a series on control loop design
There are tons of tutorials/lecture series on youtube on this subject. I think this channel is mainly about electronics. Control is far too mathematical a subject to present easily in the style of exposition selected here. Having said that, maybe experimental implementations of, say, PID controllers can be presented along with their basic principles of operation but anything beyond that would be only scratching the surface of control theory, in my opinion doing both the latter and the channel an injustice.
@@Stelios.Posantzis I don't think you have understood what I have asked ,it's not control system it's SMPS Control loop which is very essential for any power supply or Analog design engineer and there is a intuitive way or practical way of understanding of loop design and in industry people don't use too much mathematics rather they do it in intuitive way ...can you name some channel which combines mathematics and practical of SMPS Control loop design??
@@biswajit681 Sure, you don't need a thorough grounding in control systems theory in order to apply control in practice, in the industry - as long as you know to observe specific guidelines. How far this can get you and whether it will allow you to design control applications in all situations (i.e. in as many as a proper grounding in the theory would allow you, as catering for all situations is truly impossible), I do not know.
You asked about "control loop design" without qualifying that in any way - hence my original comment.
Re. control used in the particular application of SMPSs, sure, you can find something of the sort in the channel by Sam Ben Yaakov here:
www.youtube.com/@sambenyaakov
His channel is about all kinds of SMPS technology aspects and he has one or two videos on control.
He hasn't got a video on designing a control loop as far as I can remember but he does give the guidelines. Other than that, for SMPS and magnetics, it's thoroughly recommended.
Since you are not asking about the mathematical background, I don't know further examples but you can try some of these tutorials on control theory - not all are heavy on the math and some are quite short. The problem with these is that they will leave you with many more questions than answers and little to no rules to use for practical implementations to make them not worthwhile watching (for your purposes) so I'm not mentioning any.
It goes without saying that there are some deep rabbit holes here. For example, you may find out the hard way that it is not only the noise relative to circuit ground that counts and what common-mode noise is once a crappy USB charger sabotages touchscreen operation on your tablet or phone... And then there is the fun subject of mains leakage...
Thankyou. I always learn something new.
Thanks. Nice video.
Great Work ... Thank You for sharing ... Cheers :)
Great video as always! Regarding the buck/boost converter noise, or rather output ripple, maybe this is a nice segue into polyphase switching converters as a means to lower it.
Bom dia! Seus vídeos são muito bom, assisto principalmente sobre o ltspice tenho dificuldades, as vezes de entender porque está em outro idioma, as vezes posso colocar legendas com tradução, as vezes não, mas olhando várias vezes vem o entendimento. Parabéns continue com esta garra.
03:20 cateodata "zgomotul" e asa de mare incat poti sa-ti dai seama de ciclurile conductie/overshoot/blocare ale tranzistorului :)))). Asa a fost cazul la o un convertor buck pe care l-am facut in clasa a 11-ea doar cu niste comparatoare si tranzistoare bipolare
I'm curious, could the active load, which was used in the noise measurement setup, affect the results? An active load usually has its own feedback network and an amplifier so it's may be a noise source too.
I bet this can be an issue. When I tested some PSUs I used purely resistive loads to figure out the actual noise from the SMPS and not have my actual load influence that measurement.
I’m curious on how combined the AC signal with the DC level?
Hi Feri! Once on a conference at Rohde&Schwarz the speaker was Steven Sandler from Picotest, he told us "Avoid ferrite beads like the plague!" - however I've found them quite useful in several circuits containing DC/DC converters. What is your take on ferrite beads as filters for power supply noise?
What did he say was the reason to avoid using ferrite beads?
In my experience, ferrites are useful for reducing high frequency noise, but they can still cause problems if you forget that at low frequency they are inductors - when load steps are applied, if the capacitor after is small and with low ESR, you can get ringing; so you need to include the ferrite into a filter with sufficient damping;
Anyway, I'm also curios, what was the reasoning behind the statement from the R&S speaker?
@@domtom128 Sadly, he did not go in details, he just mentioned it. That's the reason I'm asking :)
@@FesZElectronics He just mentioned it without going into details and I am still wondering about the reasons. He addressed several topics regarding power supplies and told interesting stories, so there was no time to profound discussions.
@@akosbuzogany2752 I guess in the end any extra component is something to be avoided - if you can reduce noise any other way, that should be tried first.
3:50 These diagrams are drawn too small to see comfortably..
Also, I would have preferred if the capacitors were left out of the circuits since the discussion is about the inductor and the switching while the capacitors are common to both circuits and are really a separate stage (of sorts). It would drive the point home of what the difference between buck and boost converter is more easily too.
Having said that, the exposition is very clear and helps one that has never seen these circuits before to easily form the distinct concepts that are realised by them.
I would have liked the buck-boost converter to have been presented also (either as the general case from which these two circuits are derived or as their composition - given how this tutorial is structured, I suppose it would be the latter) but maybe this is a subject that can be dealt in a separate tutorial.
are you watching the video with your phone?
2:34 > "There is no such a thing as a perfectly clean electronic power supply" where do DC batteries fall in your assumptions?
I was mainly referring to electronic circuits - both linear and switching supplies, depending on the application, have non-negligible amounts of output noise.