FYI, many STM32 MCUs have a PWM mode with complimentary outputs and dead state insertion -- specifically for switched mode power supplies and brushless DC motors. I didn't really understand the connection until watching this video. Thanks!
@@PerchEagle If I understand correctly, the STM32 can generate the complimentary outputs using a single output compare channel (the 328P seems to need two, with the same compare value, but opposite output polarity). Also, the STM32 can insert dead time (neither output enabled) automatically. I think the 328P would need two timers with different TOP/BOTTOM values (or just different initial counter values?) to produce dead time.
Yes, you do. For example, the STM32G474RE available on evaluation kits has a peripheral called HRTIM. A timer capable of generate a pwm with 4GHz clock. It has multiple outputs and features that makes a synchronous buck converter easy to implement. There's also some APIs sponsored by a ST's partner called BIRICHA with professional tools used for design a 2p2z digital controller using this peripheral. Yes, z transforms and transfer functions simulated and measured all in the ecosystem. Have fun.
Sounds like How your GPUs/VGAs' Chipset and VRAM module voltage are supplied. A mosfet driver, Low and High Side Mosfets, A Capacitor, and an inductor/Coil. Interesting!
@@maxhouseman3129 yeah, i saw modern GPUs like 20 series use some kind integrated mosfet-driver because tons of Vcore phases they use and they don't use much space like older GPUs.
@@farizfadillah7557 they call those powerstages. Crazy beefy chips. One of them can easily suppy 20-30 amps without overheating and the high end ones rated for very high currents can push 50 amps. If a GPU pulls 300W at roughly 1V you have 300 amps going trough the VRM. The VRMs on modern GPUs are really the most advanced dc to dc converters out there. They convert 12V to something as low as a single volt while retaining 90+ percent efficient and delivering a few hundred watts.
Really interesting project. I am doing a PhD on power electronics and I have previously studied how to improve buck converters. There is a topology called "active clamp ZVS buck Converter" that besides using synchronous rectification with mosfets allows to have ZVS in the switching of the mosfets, which greatly reduces the switching losses. In addition, due to its behavior, it allows placing several modules in parallel to increase the total power without additional control, since it distributes the current automatically.
@@paugasolina5048 its funny you call someone a no lifer when you are on this thread chugging haterade. Must just be self reflecting or something. At least his post relates to the video.
@@juanmontes8905 How would you use the reference as a controller? Yeah, if you don’t compensate the Buck it will oscillate depending on the ESR of the inductor and output capacitor.
I'm voting for a software-implemented feedback loop here. Much more cool. Much more hackable. Much more programmable. In fact, if he solders just another halfbridge module, he can get a complete pure sinewave DC-AC with just a software mod :D Or just a multichannel DC supply that can both charge and discharge a battery :)
That's easy. Diy if you want the most bang for the buck, buy if you want it to just work. Diy requires a bunch of trial and error to get everything working good. Plus, you have to be extremely comfortable with tearing a lot of stuff apart if you get a clog/jam, etc. That goes for both diy and buy though. For context, I built a modified version of the HevORT for about $600-$700. There's nothing even close to how good and fast it is if you wanted to buy something at the same price.
@@androiduberalles not exactly the kind of budget 3d printers u can buy theses, days totally defeat the purpose of diy-ing a budget one, but for larger or complex printers diy-ing makes a lot of sense, imo just but a decent printer like the ender 3 and then u can diy a very decent 3d printer cuz u can easily print most of the parts
Sometimes, the AC resistance of the inductor can be a tricky bit, as, at short duty cycles, the apparent frequency content of the inductor current can be high enough to cause several % loss. And, of course, PCB layout can affect performance due to parasitics that reduce switching performance ....and so on, as I'm almost sicher that you know. Nice video. BTW, the ripple frequency and amplitude when in DCM, lets you do some calculations of parasitic capacitance and ACR. "Left as a proof by the student" ;-)
About the inductor, I tried some experiments with switch mode chips, and found I could not just wing it with the inductor. I had some ferrite toroids and wound them up. The uH was good but if you have the wrong core material - not so good. So anyone attempting this sort of project, look into the recommended toroid for the circuit.
Know the strength and weakness of the different technologies and select accordingly. Easy to say but development can be quite fast so the correct answer might change. Bipolar transistors might be the best choice sometimes and got it strengths.
I wish you talked about ground bounce too, at least a bit. It's quite an important thing when it comes to making compliant products that have switchmode converters. Great video though!
Damn that's some great efficiency numbers I saw today from a DC to Dc converters. Yesterday in my viva, I was asked what can be the efficiency of a DC to DC Buck Converter and books said about 80%. I think this can improve power draw of many project that are about portability. Great Video as always!
Efficiency is largely a function of size, load, and conversion factor. If you can make a switching converter larger, you can use a lower loss inductor. If the load is lower than all the magnetic and conduction losses are lower, and if the conversion is a small step than the converter can act more like a wire.
Oh yeah these days you can quite easily build DC converters that operated well above 90%. The part that is hard is when you need to balance other design aspects such as size, cost, EMI, and if you want high efficiency at a specific operating point versus across a wide range of input and output voltage and current range.
7:32....oh right, I've seen that setup before in laptop power supplies, but never really understood how they worked without a diode - this makes sense now. They're also susceptible to killing the load if the top FET shorts and sends VCC to the load directly.....
After adding a feedback system. I hope you can go forward and talk about isolated dc to dc converters. The bridge configurations. Zvs. Zcs and phase shifted pwm are very interesting topics and I would love to see what you come up with as a real circuit because I could only get the design due to lack of a workshop of any sort. But yes please a feedback system first. You have a way of making these topics simple to understand to start out
I recommend using a bootstrap IC driver for your MOSFETs, particularly where you have a high-side FET. I like the IRS2186 but the stupid thing is out of stock because of the silicon shortage. You could make your own but the tricky bit is how to control a high side driver with low-side logic. Internally these ICs might use an optocoupler (at the cost of propagation delay), others use a high voltage emitter follower (also limited in propagation and bandwidth due to miller effects). The fastest ones appear to use a transformer akin to a GDT or capacitive coupling into the inputs of a SR latch on the high side. It might make a good video topic!
The terminology Synchronous Converter is misleading as it suggests a new converter type. The design shown is still a Buck converter but with synchronous rectification, which is commonly referred to as a "Synchronous Buck". Synchronous rectification, can in concept, be applied to any use of a diode. Its commonly done on most switching mode power supply topologies or even simple mains frequency bridge rectifiers, although some applications are much easier than others. I'm not sure on the edge rates used, but be aware the long tracks between the MOSFET and the input cap and top MOSFET will eventually cause issues as substantial voltage can be developed across that short length when the switching time is short. These 3 parts should really be place right next to each other. Nice video though, it introduces a very useful concept.
Would the lower Q2 MOSFET even need to be switched on @ 6:26 ? Shouldn't current be allowed to conduct through the body diode when it's off, or is the transistor you're using not have that characteristic?
Also a neat observation you might like, if you look at the generalized/abstract schematics for buck and boost converters (using switch symbols instead of practical implementations, you will see that they are in fact the same. Just the port where power input and output are flipped around. You can make a buck converter, feed the voltage into the output, and use the input of the buck converter as the output to turn it into a boost converter! This does not take into account any practical aspects of the controller or MOSFET drive but it should be possible!
Biggest deference is that mother boards use Multiphase Bucks. Rather than having to add a ton of output capacitors, they can lower the ripple by using several inductors that take turns charging.
I like this cute little project :D It's amazing how much you can get from such a simple setup, really. If you're gonna improve for efficiency, note that the input capacitor always takes at least half of the input current, it's probably the most overlooked lossy component here. Its losses are I^2 times its ESR, which might be 100mΩ, far more than the mosfet. In fact, everything here has more resistive losses than the mosfet :D A PCB trace that is 6 times long than is wide, is heating more than the mosfet. Also, a gapped ferrite inductor would be much better. Just a few turns around a ferrite core. It would be interesting to see just how much you could get from this circuit If you'd want to, of course :D I design these things for living and I'd be happy to help :D
hey just read you design these things, i had a question if you dont mind giving your input in the vesc electric vehicle community we are looking for solutions to stepping voltages ranging from 36v to 120v down to 12v or 5v, and we were wanting to design our own purpose built modules/boards. any ideas as to what IC's we could use to base our designs around? thank you!
@@auden_builds well I don't mind, but the "which IC" example depends on the specifics of your needs. If you need something low power (standby supply) and/or very flexible, the NCP1251 flyback controller is a good starting point. If you want something fairly high power and customizable / programmable, I'd use a half bridge driver like IR2184 and a microcontroller with a HRTIM peripheral. If you need insane transient response, there's also FPGA devices with integrated analog front end (ADC/DAC) and also some opamps. Also, if you need something really compact or efficient, consider using GaNFETs. Those are some next level thingies.
7:37 - this is not the way any dc/dc converter should be routed on the PCB... I do understand it is only a concept to show an idea but nobody should learn from this. 1. The output capacitor near the output connector. It should be placed near the inductor. 2. No proper utilization of two layer PCB therefore bad ground connections. Each SMD component should have at least one via to the GND if it has at least one GND-connected PAD. 3. The connection from D2 to U1 under the inductor... WHY?! You should newer place signals under power inductors (when it is possible) 4. The input capacitor not near the inductor also. 5. The triangle loop for C2 and C3. This is bad in so many ways :( Answering the question in the title. Is this the BEST Voltage Converter? In the layout way? Definitly not. P.S. You talk so much about efficiency and yet you choose not the best power inductor type. It's quality is one of the most important things to get high efficiency.
4:19 If you care to figure out what went wrong, contact me. I can figure out what the problem is. I worked for 15+ years designing, manufacturing and testing electrical power subsystems for satellites.
Did your learn English from one or more Asian instructors? Your English seems to have several Asian influences. And are you a drawing artist? Your pen skills are impressive. Few people can retrace text and lines like you can.
Scott, this is one of the best videos about DC-DC converters i've seen!!! Such a good explanation with graphs and examples. I Appreciate your great work put in this video! Will be interested in next topic: efficient BOOST converters and are they possible?
you see a significant increase in efficiency especially when you are on low duty cycle, that means that the diode will conduct most of the time, which is the case at your mainboards DC/DC converter which has to go down to 0.9 V or some thing (low duty cycle) whilst providing 30 A. Thats why the buck of your CPU is always a synchronous one. Also you can put synchronous converts in parallel (phase shifted) to pread the load while only controlling one of them. Thats what they also do on your PCs moutherboard. Vendors referr to this as the Motherboards "phases". ( number of parallel synchronous buck stages). Also, did you realize you did not really had to choose wheather you are building a synchronous bock or boost ? Because the schematic is just the same. its just that input and output are flipped. You can actually connect one voltage rail to both sides and depneing on your duty cycle energy will flow from high to low voltage or vice versa! Thats why this topology is often referred as the DC transformer! ;)
Great scott, sir. I know it's less likely that you read this. But I love how much clearer you explain everything steps/components now. When I was first year hs, I can't understand a thing in your videos, it's full of maths and very fast. It's just great to look at but nothing to learn from. Only your same level could understand. But since they are your same level, they couldn't also learn anything. Now that I'm getting college that I understand those videos, but still they are very fast and unclear functions of components. Now you are very much more interactive. Much more clear in explaination. And much longer videos but still direct and great written videos. I actually learn many things now. Thank you so much!
Sir why do you used mosfit as switch ?? because you also can use it as diode to make things simpler (just like you used in your old vedio for reverse voltage protection ). No need of complicating things
because if he used a diode there would be a 0.3 -0.5v drop across the diode and waste power and he would get like 80 percent efficiency instead of 92 percent. in high current buck converters the diode gets pretty hot
Awesome SMPS chart. Love the quantitative data charts with graphical (schematic) information condensed well. About all I can see is having some scope graphs to further enhance. :-) Great information and details as always, thanks for sharing!
Hello Scott! Can you make a video about how GFCI (or RCCB) circuit breakers work? Also thanks for the super great video! I watch the entirety of it! HAPPY HALLOWEEN GREAT SCOTT! ALMOST FORGET ABOUT THIS! I also try to build your flickering light bulb from your old video!
do you know the schematic of a pure dc power supply, which almost resembles a battery current (9v), so that there is no audio effect, such as hum, and distortion
Sir please one time make vedio on all typologies written in smps chart and their type. One more but some basic how to read a data sheets because when I see a data sheet I not understand a single word in it (it's very very complicated for me).
The MPS 2037 has almost everything you want and is dirt cheap, you can get MPS modules are like 1 dollar each + 1 dollar shipping for me a 3-4A synchronous converter from MPS.
This is awesome timing. I am actually building this same circuit this week, except for the controller I am using a UC3843 IC and with either type II compensation network around it for current mode control. I am building this circuit primarily to test my new Picoscope 5444D and it’s frequency response analyzer tool to actually plot the bode plot and measure phase margin.
The big interference spikes at the switch moments are pretty much only there because I added a current shunt for measuring. Otherwise there would not be as much.
@@greatscottlab That may be so. Still, in my experience, switch-mode devices represent the signle most common cause of harmonic RFI. The cause may be poor design, improper use or both. What I'm saying is that they are not "simple" to design and build in order for them to perform properly and not cause RFI. Most "hobby" people don't have the gear to do proper emission testing (radiated or conducted). I'm not even gonna mention all those little cheap modules that are on the market...
I got 82% measured efficiency with my blocking oascillator (joule theif)......took me 2 hours to wind the torus...... I used used 22 awg and did like 200-250 turns around the torus in 5 layers of wraps wound bifilar. I'm currently running an LED light string on a bunch of batteried that would otherwise get thrown out. Most people go for low inductance and relatively thin wire. I found that higher inductances make the joule thief more stable and efficient and lower winding reistance helps as well. But I ca currently harvest sources producing voltages as low as 0.5 V and step it up to 95 V and it doesn't need a sepparate voltage source to opperate. It''ll run from the 0.5 V source itself. Just got in an NTE102 transistor as well, it's only rated for 100 mA Ic-e but I should be able to pull current from sources as low as 0.15-0.3 V and step it up to ~12 V. Anyways, nice boost converter.
Thanks for explaining! I've done a few integrated buck conversion designs in my circuits, and I'm really only familiar with the diode type topology, that explanation opened my eyes
Hi Scott! While I find your videos entertaining and informative, I am distressed by the use of a microcontroller to generate the PWM signal. If you were mass producing something like this then I guess a one-time-programmable micro would be OK, but why not use a 555 timer for a prototype like this?
@tech 52 The 555 is a classic , cheap, industry-standard timer chip that was designed specifically for this kind of task. Just add a couple capacitors and resistors and you have an adjustable multivibrator circuit producing the same kind of PWM signal that, with an Arduino, takes a chunk of programming. Most electronics engineers are gonna have a handful of 555s knocking about in our scrap bins - it's what Dave Jones calls a "jellybean" part - so it's what a lot of us would reach for first for a project like this.
The availability of purple PCBs has significantly increased my drive to design and order my first real PCB. It's like, once purple was invented, why even bother with other colors?
I dont have a more new ideas for you but I can totally say that ur are the most detailed videos I have ever seen. I keep trying to learn from ur videos.. thx for encouraging everyone.
Something very interesting is that synchronous buck converters and synchronous boost converters use exactly the same power components, the only difference is in the control circuits. With the manually controlled circuit you designed you should be able to switch it to a boost converter by putting power into the output pins and putting your load on the input pins. You just need to be careful of the duty cycle.
sir can we use lm5101or 5100 mosfet driver ic instead of using ir2184 driver.(because sir ir2184 is quit expensive one) ...sir at list try it......................lovely video...
Can you make a video about bidirectional dc dc converter? I learned about it recently but it's quite confusing. I saw your videos about buck/boost converter and it helped me a lot in building one. Hope you can see this comment and help me out
Actually, @0:08 ... Despite the forced popular opinion, I was ACTUALLY asking myself; " Gee why doesn't my background have a Multi meter and Oscilloscope that hasn't lived through two world wars like those there?"... AND THEN, before I could rationally suppress the intense flashbacks of ALL THOSE WRONG TURNS THAT MAY OR MAY NOT HAVE involved a "tow-truck" and tetanus-shots, , I reminded myself that not everyone is meant to have nice things that didn't have a coinciding scar or callus to reflect the work and effort involved in earning it!... and also because I never win your giveaways!... in perpetuity... with cats....
Let's Get Started and I Will See You NEXT Time! (I so love that; You are awesome, Scott). :-) YES! I am Learning. I just wish you were my teacher, when I was in school...in the 1970's. I really have learned a lot from you. I only watch quality videos about electronics. Also, in my day, even teachers didn't know the future. They could speculate but the technology was just not there yet. Now that I am old, am trying to catch up but...I can make an LED ring light up in a spectacular manner, with arduino and that is cool. I am learning about Mosfets, too. Hard to believe I built all the iRobot B21R and CoWorker Robots. I didn't design them, I just built them (I designed much of the wiring in the B21R). Anyway. Thank You, Scott. You are so good. (And I worked with MANY awesome MIT Grads!)
I have a question for anybody who can help me with it. My cousin bought a scooter from 2004, its has two sealed lead acid batteries in it in series. 12v 20Ah each.(so its 24v & 20Ah) they are obviously no good any more. so i was going to put a those Li-ion drill battery packs in parallel. now they have "BMS" built in them, but.. as they will be acting like individual cell's, will i need a 2nd "BMS" across each of them too?? PLEASE CAN ANYONE LET ME KNOW THE ANSWER TO THIS.?????
Wow. Just Wow. The signal on your Silly Scope is fascinating! And it is not what you wanted? Oh, man! It is so colorful! BTW, Merry Christmas and Happy New Year, Everyone! One Day I will get it, Scott. With your help. Thanks!
0:30 Those efficiency guidelines are just guidelines. DCM Flyback converter for instance can achieve higher efficiencies as well. Many laptop power bricks have to have a total conversion efficiency of 88% or better. They can also be used for power levels greater than 100W (I have a 130W Dell charger for instance, I would not be surprised to learn if my 200W HP charger is also a Flyback converter) Forward converters are also commonly used on medium power ATX power supplies, even good ones with 80+ ratings. (I would classify the 0:44 drawings for forward, push-pull, and and half bridge all as types of forward converter, being defined mostly by the secondary LC stage.) I have an 850W PSU and I took it apart and verified it was a 2 switch forward. LLC Converters are used where you need really high power! ATX Computer Power Supplies that are over 800W are going to be of the resonant topology.
@@n.shiina8798 it's often a cost thing. I got a Xbox 360 power brick that's only 120W and it some reason is also an LLC converter. Funny to compare that to the other extreme being the Dell 130W adapter and it's a synchronous Flyback with integrated PFC all in 1 chip!
@@power-max i dont usually believe LLC could costs cheaper than flyback but i could be wrong since we're talking about big bulk purchase here. it's a good thing to see LLC being deployed more, though
Hey @GreatScott! I was thinking that is it not possible to just connect the pwm signal from arduino to a NOT gate followed by a delay circuit at either of the complimentary output instead of MOSFET driver? Like I'm well aware why you're using it tho... Just asking...
Okay so I am currently looking here and there to find something useful, but failed so came to the greatest source of all - yt comment section. I want to power up the project using RPi with an LCD and cameras, etc. and the problem is I kinda have to power it up from a 1S LiPo. The problem is all the 3.7 to 5 DC-DC boosters I find have the max output of 2A or so... Afaik I need more than 3A, so can anyone help me? Maybe I'm just blind or dumb, idk...
Maybe you could try zero voltage switching (ZVS) design, it is a bit more complicated, but the efficiency could reach 99% because it eliminated MOSFET switching loss. MOSFET switching is not perfect. It will have a short transition period in resistive mode between on off cycle, contributing to power loss, especially for high-frequency operation in pursuing smaller inductors and circuit footprint.
DIYperks just made an awesome usb-c mic. I was wondering if you could help make the pcb better? He said he doesn't know much about that stuff. But you are the MASTER!!!! So maybe video idea? Collaboration with Matt cleaning up his circut?
💚 exuse me but I have a question . What is that think on the fan in the left of the potentiometer. That show Amp & temperature ecc ( that DISPLAY) 😇 THANK YOU🤍 IF ANYONE CAN HELP ME
GreatScott Good day Please make a DC UPS zero transfer time for router with 5v,9v,12v output @5A that will last for 3-4days. With Built in charger and BMS
Why the 10k R3 and R4? (between the gate and source of the switches) Good driver design with the gate resistor paralleled by a diode, that stops the ring that can cook your driver, shuts off the switches quickly and also stops parasitic turn on in the synchronous rectifier switch. It took me far too much experimentation to learn those lessons... but my multiphase buck designs are running 96-97% efficient, pretty cool stuff. Managing the ripple current by inductor and Fz selection is the other major way to reduce the losses.
That: "Stay creative, and I will see you next time!" goes crazier every time. I love it!
😁
Haha yeah
Keep it, otherwise I'm gonna miss it.
so am i
@@greatscottlabwhy jlcpcb needs $6 to ship and a pcb costs $2
FYI, many STM32 MCUs have a PWM mode with complimentary outputs and dead state insertion -- specifically for switched mode power supplies and brushless DC motors. I didn't really understand the connection until watching this video. Thanks!
Ooooh makes a lot of sense! I always wondered why every timer had 2 output pins
If you and Batu Gunduz meaning the 2 output units for each timer then the ATmega328p has the same scheme.
@@PerchEagle If I understand correctly, the STM32 can generate the complimentary outputs using a single output compare channel (the 328P seems to need two, with the same compare value, but opposite output polarity). Also, the STM32 can insert dead time (neither output enabled) automatically. I think the 328P would need two timers with different TOP/BOTTOM values (or just different initial counter values?) to produce dead time.
@@markday3145 ok, let me check the stm32 datasheet for this point.
Yes, you do. For example, the STM32G474RE available on evaluation kits has a peripheral called HRTIM. A timer capable of generate a pwm with 4GHz clock. It has multiple outputs and features that makes a synchronous buck converter easy to implement. There's also some APIs sponsored by a ST's partner called BIRICHA with professional tools used for design a 2p2z digital controller using this peripheral. Yes, z transforms and transfer functions simulated and measured all in the ecosystem. Have fun.
Sounds like How your GPUs/VGAs' Chipset and VRAM module voltage are supplied. A mosfet driver, Low and High Side Mosfets, A Capacitor, and an inductor/Coil. Interesting!
Oh, you're right!
@@maxhouseman3129 yeah, i saw modern GPUs like 20 series use some kind integrated mosfet-driver because tons of Vcore phases they use and they don't use much space like older GPUs.
Yeh most efficient way to convert power. There are powerstages that reach like 95% efficiency under normal operation.
@@farizfadillah7557 they call those powerstages. Crazy beefy chips. One of them can easily suppy 20-30 amps without overheating and the high end ones rated for very high currents can push 50 amps. If a GPU pulls 300W at roughly 1V you have 300 amps going trough the VRM. The VRMs on modern GPUs are really the most advanced dc to dc converters out there. They convert 12V to something as low as a single volt while retaining 90+ percent efficient and delivering a few hundred watts.
I will say this too. But you already say it
Really interesting project.
I am doing a PhD on power electronics and I have previously studied how to improve buck converters.
There is a topology called "active clamp ZVS buck Converter" that besides using synchronous rectification with mosfets allows to have ZVS in the switching of the mosfets, which greatly reduces the switching losses. In addition, due to its behavior, it allows placing several modules in parallel to increase the total power without additional control, since it distributes the current automatically.
noone cares no lifer
Electronics aren’t real dude
that's awesome! Would be great to read the research you write about this.
Interesting
@@paugasolina5048 its funny you call someone a no lifer when you are on this thread chugging haterade. Must just be self reflecting or something. At least his post relates to the video.
I am looking forward to learn how to add feedback system for this supper simple converter. That would be perfect. 👍
Fingers crossed!
I think a tl431 could be a good and cheap option, but I'm not sure if it will oscillate by itself
@@juanmontes8905 How would you use the reference as a controller? Yeah, if you don’t compensate the Buck it will oscillate depending on the ESR of the inductor and output capacitor.
I'm voting for a software-implemented feedback loop here.
Much more cool. Much more hackable. Much more programmable.
In fact, if he solders just another halfbridge module, he can get a complete pure sinewave DC-AC with just a software mod :D
Or just a multichannel DC supply that can both charge and discharge a battery :)
@@dedamarsovac the Rp2040 can be a good option, but you will need a independent power supply for the uc
Seeing that ad for the Alfa Flame Scam “heater” is quite an embarrassment to your channel. Those advertisers need to be in prison.
Nice, another video. But im still waiting for The 3d printer diy or buy :D, but keep up The great work!
Maybe one day!
@@greatscottlab I still hope :D
That's easy. Diy if you want the most bang for the buck, buy if you want it to just work. Diy requires a bunch of trial and error to get everything working good. Plus, you have to be extremely comfortable with tearing a lot of stuff apart if you get a clog/jam, etc. That goes for both diy and buy though.
For context, I built a modified version of the HevORT for about $600-$700. There's nothing even close to how good and fast it is if you wanted to buy something at the same price.
@@androiduberalles thats true
@@androiduberalles not exactly the kind of budget 3d printers u can buy theses, days totally defeat the purpose of diy-ing a budget one, but for larger or complex printers diy-ing makes a lot of sense, imo just but a decent printer like the ender 3 and then u can diy a very decent 3d printer cuz u can easily print most of the parts
Sometimes, the AC resistance of the inductor can be a tricky bit, as, at short duty cycles, the apparent frequency content of the inductor current can be high enough to cause several % loss. And, of course, PCB layout can affect performance due to parasitics that reduce switching performance ....and so on, as I'm almost sicher that you know. Nice video. BTW, the ripple frequency and amplitude when in DCM, lets you do some calculations of parasitic capacitance and ACR. "Left as a proof by the student" ;-)
Cheers🍷
Yea
Those are all the fine details. Maybe one day I can get to such detailed topics :-)
About the inductor, I tried some experiments with switch mode chips, and found I could not just wing it with the inductor. I had some ferrite toroids and wound them up. The uH was good but if you have the wrong core material - not so good. So anyone attempting this sort of project, look into the recommended toroid for the circuit.
Dude, how can I get to know so much? Any books you would recommend on power electronics or courses?
How to increase the efficiency of most circuits 101:
Replace bipolar transistor with a FET and some complicated logic that emulates the bipolar.
Know the strength and weakness of the different technologies and select accordingly. Easy to say but development can be quite fast so the correct answer might change.
Bipolar transistors might be the best choice sometimes and got it strengths.
I wish you talked about ground bounce too, at least a bit. It's quite an important thing when it comes to making compliant products that have switchmode converters.
Great video though!
I can put the topic on my to do list :-)
@@greatscottlab Please do. Ground bounce is a real pain in the ass - especially in mixed-signal designs.
Damn that's some great efficiency numbers I saw today from a DC to Dc converters.
Yesterday in my viva, I was asked what can be the efficiency of a DC to DC Buck Converter and books said about 80%.
I think this can improve power draw of many project that are about portability.
Great Video as always!
Thanks mate :-)
Ok
Efficiency is largely a function of size, load, and conversion factor. If you can make a switching converter larger, you can use a lower loss inductor. If the load is lower than all the magnetic and conduction losses are lower, and if the conversion is a small step than the converter can act more like a wire.
Oh yeah these days you can quite easily build DC converters that operated well above 90%. The part that is hard is when you need to balance other design aspects such as size, cost, EMI, and if you want high efficiency at a specific operating point versus across a wide range of input and output voltage and current range.
7:32....oh right, I've seen that setup before in laptop power supplies, but never really understood how they worked without a diode - this makes sense now. They're also susceptible to killing the load if the top FET shorts and sends VCC to the load directly.....
After adding a feedback system. I hope you can go forward and talk about isolated dc to dc converters. The bridge configurations. Zvs. Zcs and phase shifted pwm are very interesting topics and I would love to see what you come up with as a real circuit because I could only get the design due to lack of a workshop of any sort. But yes please a feedback system first. You have a way of making these topics simple to understand to start out
I recommend using a bootstrap IC driver for your MOSFETs, particularly where you have a high-side FET. I like the IRS2186 but the stupid thing is out of stock because of the silicon shortage. You could make your own but the tricky bit is how to control a high side driver with low-side logic. Internally these ICs might use an optocoupler (at the cost of propagation delay), others use a high voltage emitter follower (also limited in propagation and bandwidth due to miller effects). The fastest ones appear to use a transformer akin to a GDT or capacitive coupling into the inputs of a SR latch on the high side. It might make a good video topic!
A mechanism I'm experimenting with involves a flyback with two feedbacks...
One for the switcher, one for the Ideal Diode - I mean Synchronous Switch
The terminology Synchronous Converter is misleading as it suggests a new converter type. The design shown is still a Buck converter but with synchronous rectification, which is commonly referred to as a "Synchronous Buck". Synchronous rectification, can in concept, be applied to any use of a diode. Its commonly done on most switching mode power supply topologies or even simple mains frequency bridge rectifiers, although some applications are much easier than others.
I'm not sure on the edge rates used, but be aware the long tracks between the MOSFET and the input cap and top MOSFET will eventually cause issues as substantial voltage can be developed across that short length when the switching time is short. These 3 parts should really be place right next to each other.
Nice video though, it introduces a very useful concept.
I strongly suggest you to get 0.5mm tin. Your smd soldering will look much nicer and you can control the amount much more precisely.
He's way too arrogant to accept comments on how poor is the quality of his solder joints 😆
Would the lower Q2 MOSFET even need to be switched on @ 6:26 ? Shouldn't current be allowed to conduct through the body diode when it's off, or is the transistor you're using not have that characteristic?
The body diode creates more power losses than the MOSFET. You want to use it as little as possible.
Thanks for clarifying, Keep up the good videos.
it hurts so much to see you go over your writing again and again and again. and again. i can just feel it bleeding through into the next 5 pages.
Also a neat observation you might like, if you look at the generalized/abstract schematics for buck and boost converters (using switch symbols instead of practical implementations, you will see that they are in fact the same. Just the port where power input and output are flipped around. You can make a buck converter, feed the voltage into the output, and use the input of the buck converter as the output to turn it into a boost converter! This does not take into account any practical aspects of the controller or MOSFET drive but it should be possible!
I think these converters are used in motherboards to powering cpu's. Great tutorial as always thanks Great Scott
Yes, they're used on that, sometimes even is a single IC with both MOSFETs inside of the same package with the control logic
@@juanmontes8905 thanks for additional information
Biggest deference is that mother boards use Multiphase Bucks. Rather than having to add a ton of output capacitors, they can lower the ripple by using several inductors that take turns charging.
Synchronous ones also have very low dropout voltage.
Thanks sir, you made vedio very close to my request but please 1 time make a vedio on how to make highest efficiency diy lab bench power supply
I like this cute little project :D
It's amazing how much you can get from such a simple setup, really.
If you're gonna improve for efficiency, note that the input capacitor always takes at least half of the input current, it's probably the most overlooked lossy component here. Its losses are I^2 times its ESR, which might be 100mΩ, far more than the mosfet.
In fact, everything here has more resistive losses than the mosfet :D
A PCB trace that is 6 times long than is wide, is heating more than the mosfet.
Also, a gapped ferrite inductor would be much better. Just a few turns around a ferrite core.
It would be interesting to see just how much you could get from this circuit
If you'd want to, of course :D
I design these things for living and I'd be happy to help :D
hey just read you design these things, i had a question if you dont mind giving your input
in the vesc electric vehicle community we are looking for solutions to stepping voltages ranging from 36v to 120v down to 12v or 5v, and we were wanting to design our own purpose built modules/boards. any ideas as to what IC's we could use to base our designs around?
thank you!
@@auden_builds well I don't mind, but the "which IC" example depends on the specifics of your needs.
If you need something low power (standby supply) and/or very flexible, the NCP1251 flyback controller is a good starting point.
If you want something fairly high power and customizable / programmable, I'd use a half bridge driver like IR2184 and a microcontroller with a HRTIM peripheral.
If you need insane transient response, there's also FPGA devices with integrated analog front end (ADC/DAC) and also some opamps.
Also, if you need something really compact or efficient, consider using GaNFETs. Those are some next level thingies.
7:37 - this is not the way any dc/dc converter should be routed on the PCB... I do understand it is only a concept to show an idea but nobody should learn from this.
1. The output capacitor near the output connector. It should be placed near the inductor.
2. No proper utilization of two layer PCB therefore bad ground connections. Each SMD component should have at least one via to the GND if it has at least one GND-connected PAD.
3. The connection from D2 to U1 under the inductor... WHY?! You should newer place signals under power inductors (when it is possible)
4. The input capacitor not near the inductor also.
5. The triangle loop for C2 and C3.
This is bad in so many ways :(
Answering the question in the title. Is this the BEST Voltage Converter? In the layout way? Definitly not.
P.S. You talk so much about efficiency and yet you choose not the best power inductor type. It's quality is one of the most important things to get high efficiency.
4:19 If you care to figure out what went wrong, contact me. I can figure out what the problem is. I worked for 15+ years designing, manufacturing and testing electrical power subsystems for satellites.
Did your learn English from one or more Asian instructors? Your English seems to have several Asian influences. And are you a drawing artist? Your pen skills are impressive. Few people can retrace text and lines like you can.
If only JLC had a matt green solder mask it would be my number one shop....
hey could you build one to turn 12 volt to 48 volts at 1500 watts as this would hella useful for Ebikes
Great project! I feel like someone need to buy you a breadboard 😉
Thank you! Really love power supply projects, explains the basics very well.
Glad it was helpful!
Scott, this is one of the best videos about DC-DC converters i've seen!!! Such a good explanation with graphs and examples. I Appreciate your great work put in this video! Will be interested in next topic: efficient BOOST converters and are they possible?
Good video bro I am from Kerala India 🇮🇳 I waiting for next video 🙏
Thanks :-)
to JLPCB, no i wont pay $6 shipping for a $2 board. i will fabricate it myself, with photoresist
the 6 dollar shipping is definitely a lie, i mean shipping a letter is more like under a dollar at most
The alternatives are more expensive, at least the ones i know
You go girl
Bro I have to pay 50 euro shipping
@@ancientlink0 change the shopping option to International global shipping
you see a significant increase in efficiency especially when you are on low duty cycle, that means that the diode will conduct most of the time, which is the case at your mainboards DC/DC converter which has to go down to 0.9 V or some thing (low duty cycle) whilst providing 30 A.
Thats why the buck of your CPU is always a synchronous one.
Also you can put synchronous converts in parallel (phase shifted) to pread the load while only controlling one of them.
Thats what they also do on your PCs moutherboard. Vendors referr to this as the Motherboards "phases". ( number of parallel synchronous buck stages).
Also, did you realize you did not really had to choose wheather you are building a synchronous bock or boost ?
Because the schematic is just the same. its just that input and output are flipped.
You can actually connect one voltage rail to both sides and depneing on your duty cycle energy will flow from high to low voltage or vice versa!
Thats why this topology is often referred as the DC transformer! ;)
Can list some mini projects for our academic courses as we need some good ones and i know you have some up !
Great scott, sir. I know it's less likely that you read this. But I love how much clearer you explain everything steps/components now.
When I was first year hs, I can't understand a thing in your videos, it's full of maths and very fast. It's just great to look at but nothing to learn from. Only your same level could understand. But since they are your same level, they couldn't also learn anything. Now that I'm getting college that I understand those videos, but still they are very fast and unclear functions of components.
Now you are very much more interactive. Much more clear in explaination. And much longer videos but still direct and great written videos. I actually learn many things now. Thank you so much!
Gooood and like ❤️❤️❤️❤️❤️❤️❤️❤️👉
I love that GreatScott finally uses ferrules in his projects! Upgrade due to last video :D
Great series! I would really love to see how to implement an isolated switching converter. The magnetics can be a bit intimidating.
Excellent 👏👏
Sir why do you used mosfit as switch ?? because you also can use it as diode to make things simpler (just like you used in your old vedio for reverse voltage protection ). No need of complicating things
because if he used a diode there would be a 0.3 -0.5v drop across the diode and waste power and he would get like 80 percent efficiency instead of 92 percent.
in high current buck converters the diode gets pretty hot
I always imagined great scott to be a 50 yr old retiree
Awesome SMPS chart. Love the quantitative data charts with graphical (schematic) information condensed well. About all I can see is having some scope graphs to further enhance. :-) Great information and details as always, thanks for sharing!
Neglect-able = Negligible?
Glad you enjoyed it!
Where can we download the chart?
www.kynixsemiconductor.com/upload/image/20180523/SMPSChart_20180523.pdf
Hello Scott! Can you make a video about how GFCI (or RCCB) circuit breakers work?
Also thanks for the super great video! I watch the entirety of it!
HAPPY HALLOWEEN GREAT SCOTT! ALMOST FORGET ABOUT THIS! I also try to build your flickering light bulb from your old video!
Well he does have a video on RCCB, but it's not like teardown style tho... :(
ruclips.net/video/DWsVvdd8QJ4/видео.html
It'd be interesting to see a basic buck converter topology with an "ideal diode" (MOSFET + Current Mirror) in place of the normal diode.
Great video as always. I’d love to see you explain an isolated dc-dc topology.
do you know the schematic of a pure dc power supply, which almost resembles a battery current (9v), so that there is no audio effect, such as hum, and distortion
Sir please one time make vedio on all typologies written in smps chart and their type. One more but some basic how to read a data sheets because when I see a data sheet I not understand a single word in it (it's very very complicated for me).
10:17 Deutsches Rotes Kreuz stift!
Bist du Sanitäter??!
Your calming tone and drawing prowess is Bob Ross lvl. And that is rare.
Neon Genesis Evangelion fans be like:
"OMG BEST PCB COLOR SCHEME!"
💗💗💗💗
The MPS 2037 has almost everything you want and is dirt cheap, you can get MPS modules are like 1 dollar each + 1 dollar shipping for me a 3-4A synchronous converter from MPS.
Thanks for the tip :-)
@@greatscottlab sorry, I meant 2307
This is awesome timing. I am actually building this same circuit this week, except for the controller I am using a UC3843 IC and with either type II compensation network around it for current mode control. I am building this circuit primarily to test my new Picoscope 5444D and it’s frequency response analyzer tool to actually plot the bode plot and measure phase margin.
4:40 always 🥲
You should try making dual phase converters too. Because they're fun :3
I’m looking at those scope traces and thinking “ahh... all that lovely RFI”...
The big interference spikes at the switch moments are pretty much only there because I added a current shunt for measuring. Otherwise there would not be as much.
@@greatscottlab That may be so. Still, in my experience, switch-mode devices represent the signle most common cause of harmonic RFI. The cause may be poor design, improper use or both. What I'm saying is that they are not "simple" to design and build in order for them to perform properly and not cause RFI. Most "hobby" people don't have the gear to do proper emission testing (radiated or conducted). I'm not even gonna mention all those little cheap modules that are on the market...
Nice work 👍
Can you make type - c charger from 12v battery supply
Yes, there's a similar part to the datasheet he showed that's perfect for this. www.ti.com/lit/an/snvaa33/snvaa33.pdf
I got 82% measured efficiency with my blocking oascillator (joule theif)......took me 2 hours to wind the torus...... I used used 22 awg and did like 200-250 turns around the torus in 5 layers of wraps wound bifilar. I'm currently running an LED light string on a bunch of batteried that would otherwise get thrown out.
Most people go for low inductance and relatively thin wire. I found that higher inductances make the joule thief more stable and efficient and lower winding reistance helps as well. But I ca currently harvest sources producing voltages as low as 0.5 V and step it up to 95 V and it doesn't need a sepparate voltage source to opperate. It''ll run from the 0.5 V source itself.
Just got in an NTE102 transistor as well, it's only rated for 100 mA Ic-e but I should be able to pull current from sources as low as 0.15-0.3 V and step it up to ~12 V.
Anyways, nice boost converter.
OH MY GOD ..... so SIMPLE ! ..... and too much commercials. Thumbs DOWN
Thanks for explaining! I've done a few integrated buck conversion designs in my circuits, and I'm really only familiar with the diode type topology, that explanation opened my eyes
Glad it was helpful!
boost converter has the diode turned on all the time, so this tech is useless for step up right?
play
Hi Scott! While I find your videos entertaining and informative, I am distressed by the use of a microcontroller to generate the PWM signal. If you were mass producing something like this then I guess a one-time-programmable micro would be OK, but why not use a 555 timer for a prototype like this?
@tech 52 The 555 is a classic , cheap, industry-standard timer chip that was designed specifically for this kind of task. Just add a couple capacitors and resistors and you have an adjustable multivibrator circuit producing the same kind of PWM signal that, with an Arduino, takes a chunk of programming. Most electronics engineers are gonna have a handful of 555s knocking about in our scrap bins - it's what Dave Jones calls a "jellybean" part - so it's what a lot of us would reach for first for a project like this.
The availability of purple PCBs has significantly increased my drive to design and order my first real PCB. It's like, once purple was invented, why even bother with other colors?
Man purple is so last decade, the new hot is Sakura Pink.
man, i love the drawings that you do. they're so... precise
omg, I just realized that is a 15k Oscilloscope...
I dont have a more new ideas for you but I can totally say that ur are the most detailed videos I have ever seen. I keep trying to learn from ur videos.. thx for encouraging everyone.
Can we make a power supply with this circuit? I really love very high efficient power supply that are fan less and powerful
Sure
someone finaly decided to use proteus instead of altium interesting
Something very interesting is that synchronous buck converters and synchronous boost converters use exactly the same power components, the only difference is in the control circuits. With the manually controlled circuit you designed you should be able to switch it to a boost converter by putting power into the output pins and putting your load on the input pins. You just need to be careful of the duty cycle.
interesting, did not notice that on my own before :)
Sometimes I wonder how much of what you say I'm actually remembering since I never make anything that you do
sir can we use lm5101or 5100 mosfet driver ic instead of using ir2184 driver.(because sir ir2184 is quit expensive one) ...sir at list try it......................lovely video...
Hi. What software do you use to actually draw the pcbs?
Wanting to get into it and try
I would appreciate a recommendation.
Did you notice that synchronous Buck and boost are identical? Just flip source and load, and you have a new video.
1:00 "But before I do that..."
Ngl, I was going to fast forward already XD
Can you build a mobile phone signal booster to use in rural areas? I couldn't find any proper tutorial on the internet for building such a device
Can you make a video about bidirectional dc dc converter? I learned about it recently but it's quite confusing. I saw your videos about buck/boost converter and it helped me a lot in building one. Hope you can see this comment and help me out
Actually, @0:08 ... Despite the forced popular opinion, I was ACTUALLY asking myself; " Gee why doesn't my background have a Multi meter and Oscilloscope that hasn't lived through two world wars like those there?"... AND THEN, before I could rationally suppress the intense flashbacks of ALL THOSE WRONG TURNS THAT MAY OR MAY NOT HAVE involved a "tow-truck" and tetanus-shots, , I reminded myself that not everyone is meant to have nice things that didn't have a coinciding scar or callus to reflect the work and effort involved in earning it!... and also because I never win your giveaways!... in perpetuity... with cats....
from where should i buy my electronic components in India? please help me.
Let's Get Started and I Will See You NEXT Time! (I so love that; You are awesome, Scott). :-)
YES! I am Learning. I just wish you were my teacher, when I was in school...in the 1970's.
I really have learned a lot from you. I only watch quality videos about electronics. Also, in my day, even teachers didn't know the future. They could speculate but the technology was just not there yet. Now that I am old, am trying to catch up but...I can make an LED ring light up in a spectacular manner, with arduino and that is cool. I am learning about Mosfets, too. Hard to believe I built all the iRobot B21R and CoWorker Robots. I didn't design them, I just built them (I designed much of the wiring in the B21R). Anyway. Thank You, Scott. You are so good. (And I worked with MANY awesome MIT Grads!)
Sir mobile phone fast changing how its work please explain
I have a question for anybody who can help me with it. My cousin bought a scooter from 2004, its has two sealed lead acid batteries in it in series. 12v 20Ah each.(so its 24v & 20Ah) they are obviously no good any more. so i was going to put a those Li-ion drill battery packs in parallel. now they have "BMS" built in them, but.. as they will be acting like individual cell's, will i need a 2nd "BMS" across each of them too?? PLEASE CAN ANYONE LET ME KNOW THE ANSWER TO THIS.?????
and do you remenber 2 weeks ago i asker you that have you been watching all these days. this is just anather account
could you explain how to connect multiple buck boost converters in parallel for more current output
What is the name and model of that power meter / module with the LCD and fan on it?
Wow. Just Wow. The signal on your Silly Scope is fascinating! And it is not what you wanted? Oh, man! It is so colorful! BTW, Merry Christmas and Happy New Year, Everyone! One Day I will get it, Scott. With your help. Thanks!
0:30 Those efficiency guidelines are just guidelines. DCM Flyback converter for instance can achieve higher efficiencies as well. Many laptop power bricks have to have a total conversion efficiency of 88% or better. They can also be used for power levels greater than 100W (I have a 130W Dell charger for instance, I would not be surprised to learn if my 200W HP charger is also a Flyback converter)
Forward converters are also commonly used on medium power ATX power supplies, even good ones with 80+ ratings. (I would classify the 0:44 drawings for forward, push-pull, and and half bridge all as types of forward converter, being defined mostly by the secondary LC stage.) I have an 850W PSU and I took it apart and verified it was a 2 switch forward.
LLC Converters are used where you need really high power! ATX Computer Power Supplies that are over 800W are going to be of the resonant topology.
some power brick under 200W uses LLC nowadays
@@n.shiina8798 it's often a cost thing. I got a Xbox 360 power brick that's only 120W and it some reason is also an LLC converter. Funny to compare that to the other extreme being the Dell 130W adapter and it's a synchronous Flyback with integrated PFC all in 1 chip!
@@power-max i dont usually believe LLC could costs cheaper than flyback but i could be wrong since we're talking about big bulk purchase here. it's a good thing to see LLC being deployed more, though
@@n.shiina8798 my favorite LLC converter is the DRSSTC type 🤪
@@power-max lol. sparks goes brrr!
Hey @GreatScott! I was thinking that is it not possible to just connect the pwm signal from arduino to a NOT gate followed by a delay circuit at either of the complimentary output instead of MOSFET driver? Like I'm well aware why you're using it tho... Just asking...
Okay so I am currently looking here and there to find something useful, but failed so came to the greatest source of all - yt comment section.
I want to power up the project using RPi with an LCD and cameras, etc. and the problem is I kinda have to power it up from a 1S LiPo. The problem is all the 3.7 to 5 DC-DC boosters I find have the max output of 2A or so... Afaik I need more than 3A, so can anyone help me? Maybe I'm just blind or dumb, idk...
Maybe you could try zero voltage switching (ZVS) design, it is a bit more complicated, but the efficiency could reach 99% because it eliminated MOSFET switching loss. MOSFET switching is not perfect. It will have a short transition period in resistive mode between on off cycle, contributing to power loss, especially for high-frequency operation in pursuing smaller inductors and circuit footprint.
DIYperks just made an awesome usb-c mic. I was wondering if you could help make the pcb better? He said he doesn't know much about that stuff. But you are the MASTER!!!! So maybe video idea? Collaboration with Matt cleaning up his circut?
💚 exuse me but I have a question . What is that think on the fan in the left of the potentiometer. That show Amp & temperature ecc ( that DISPLAY) 😇
THANK YOU🤍
IF ANYONE CAN HELP ME
My project solar cell mppt's also use synchronous buck converter(sbc). i only have 83% efficiency. Using IR2104 IC to drive pwm from arduino to sbc
Scott I want to turn 480vdc to atleast 40vdc atleast 400w how would you go on about this
GreatScott
Good day Please make a DC UPS zero transfer time for router with 5v,9v,12v output @5A that will last for 3-4days. With Built in charger and BMS
Why the 10k R3 and R4? (between the gate and source of the switches) Good driver design with the gate resistor paralleled by a diode, that stops the ring that can cook your driver, shuts off the switches quickly and also stops parasitic turn on in the synchronous rectifier switch. It took me far too much experimentation to learn those lessons... but my multiphase buck designs are running 96-97% efficient, pretty cool stuff. Managing the ripple current by inductor and Fz selection is the other major way to reduce the losses.
Where can I purchase a 12v DC to 28v DC step up converter about 200Watt 6amp output, that is ISOLATED with separate transformer contained?
I love it good
Keep uploading videos like this
👍
at 9:12: LM61495, LM61480, LM62460 are all out of stock.. any alternatives?