Electronics Tutorial - Handling a Boost SMPS ripple using LTspice

[@WalidIssa]

Brilliant. A few in this world keep digging for such details which make us feel like experts. Enjoyed and Loved this video and how you present it. Please do more of these. I believe many professors don't know things like that. Hats off

[@yt4krist0f]

Exactly... I just found this video but it's awesome to watch. Every school class should have been like this. It's interesting, useful, practical, etc... I ery much like the way of his thinking, the whole debugging process, the root cause analyzation, the coverage. Keep on FesZ!!

[@p_mouse8676]

Excellent video! Really shows how to understand relationships between problems and how to model them. Also explained much better than some bigger well known KZbinrs out there. Keep up the good work! On the subject itself: one thing I was missing is the ringing and noise that's caused by the internal MOSFET when switching.

[@FesZElectronics]

Hello Piet! I'm happy you enjoyed this video! If I understood your question correctly, the Mosfet (in this case its a BJT, but that's not important), lets call it the switching element; does not cause that much noise on its own. The ringing you see in switch nodes mostly is coming from the stray capacitance from the switch node to ground and stray inductances in the traces. Another common problem in boost circuits is the parallel capacitance and reverse recovery time of the diode (but this should be included in the diode model) and the parallel capacitance of the inductor. The real life switching element also has these capacitances and inductances and stuff, but in this simulations case this component is included into the LT3467 component. Because of the voltage tripler stage any specific switching node noise gets filtered out by the long strain of diodes and capacitors, I think that is why it was missing, or it was just much smaller than all the other noise sources in the system.

[@p_mouse8676]

@@FesZElectronics yes. That's correct. For switching converters with an external switching element it can be worse. The thing is that not only the noise is an issue, but EMI as well. So sometimes the output looks clean, because all the caps filter everything out, but at the same time the circuit is sending a lot of noise "through the air".

[@FesZElectronics]

@Piet Mujis I fully agree about the radiated EMI part. The problem is that its not really possible to simulate radiated emissions with LTspice... Regarding the internal/external switch element, I would lean on saying that the external one can be better, I had a case in which I was working on a low power (6V, 100mA) supply with internal transistor; and for some reason the switch was designed to have a 1-2ns rise/fall time. Considering the power output this was complete overkill but there was nothing to do about it.. This should have reduced power disipation but it ended up creating huge EMI problems. If the transistor would have been external, you could simply reduce the rise/fall time with gate resistors.

[@qfwfqqfwfq6249]

I've looked for this kind of explanation for a long time, and I've found it now by you. Thanks a lot.

[@joet4348]

Man this video is so good. Need to watch it about 3 more times though.

[@EinzigfreierName]

This is very interesting and usefull content. Very well explained and easy to understand. Thanks for sharing with us.

[@petr_e]

Thank you very much for a great lecture on SMPS! I've met all kinds of problems you've described and your explanation and means to solve troubles are really very useful!

[@FesZElectronics]

I'm happy this video helped you! Where there any other "mysterious" problems you ran into that gave you trouble?

[@gammoudirabia6093]

thank you very much! it is a very usefull tutorial.

[@FesZElectronics]

I'm happy you enjoyed it! Let me know if there are any specific topics you might be interested in

[@electronicsdiypcbdesignpro6881]

wonderful electronic tutorial about SMPS

[@FesZElectronics]

I'm happy you enjoyed it! Let me know if there are any specific SMPS related topics you might be interested in, maybe I could cover them in a future video

[@omkarkhade4602]

Thank you for sharing this knowledge.

[@TheCitygear]

Thank you for your VIDEO!

[@3bmon3em]

Does real hardware design care about this very small noise? I mean I watch a lot of videos about power supply but it seems that about 100mV of noise is considered good enough and no one cares about cleaning it more than that. Love your videos by the way ❤️👏

[@FesZElectronics]

It highly depends on the application I guess. In something like an audio circuit any noise is usually bad; but also if you need to pass EMI emission tests, you want to keep noise as low as possible. Another thing to consider is the output voltage - 0.1V ripple in 24v can be neglected, but if the output is 0.8V (like core voltages in processors) its a big issue.

[@KamleshGadhvana]

very nice work thank you!

[@malap123]

Very intriguing

[@akashtanwar1939]

Awesome

[@shahzaibshamim6524]

Do you also work with microcontrollers or just with hardware?

[@FesZElectronics]

On this channel I only did hardware until now. I sometimes work with microcontrollers but I'm not a good programmer, so I try to stick to presenting things I actually know. I may cover the HW aspects of microcontrollers at some point, who knows. Do you have any specific topic in mind?

[@shahzaibshamim6524]

@@FesZElectronics not now, just asking. But you are presenting very awesome topics of hardware designs with simulations. Good work!

[@FesZElectronics]

Thank you! I will try to keep making good quality videos in the future

[@preetham56]

Awesome