Should you buy a GaN Power Adapter? Or is it a scam? || Testing GaN FETs! 

So in short GAN is not a scam but the adapter that didn't have one in it is! :)

GaN and Mosfet: _fighting_ Silicon Carbide: _Record the fight_ IGBT: _watching from far away_ Bjt: *in the corner* Ujt: _buried in the grave_ Thyristor family: 👏👏 *impressive* Vacuum tube: _in the hall of fame_

Your mid-air circuit has some sort of ElectroBOOM vibes to it, minus the explosions though.

I think what's more important to most consumers than minor savings on their electric bill is actually the simple fact that a GaN charger can be physically smaller than a traditional silicon based one of equivalent power output.

GaN Fets are maybe not a scam but some Products wich say they offer GaN Fets :D Because they use traditional cheap mosfets and to increase their margin with the GaN selling point

"Stay creative....and I will see you next time!!!" *Covers webcam just in case.

Simply swapping a GaN FET into a given switching circuit will provide only modest gains; the main advantage is that you can then use a higher switching frequency without the gate charge becoming a limiting factor for efficiency, so you can reduce the size of your other components and by extension reduce losses in them too. You also covered both gate charge and on resistance independently, but the real benefit with a GaN is the ratio or relationship between these. You can easily get silicon MOSFETs with on resistances way lower than the one you looked at, but it would have a huge gate charge which increases losses elsewhere in the circuit. This relationship can be considered a "figure of merit" for comparing switching transistors, and it's simply much better in GaN fets at any size/rating. In general, the end result is much *smaller* power adapters with slightly better efficiency; in practice the efficiency of a USB adapter really won't have a major impact on somebody's power bill (because USB devices are only a small fraction of somebody's total power bill), but having a smaller adapter for the same output is a definite advantage to most people! As another aside, silicon carbide is also starting to be used in power applications (similar "figure of merit" improvements compared to silicon). Due to their characteristics, you'll usually see GaN used in lower power and lower voltage applications (like consumer power adapters) while SiC is often selected for higher voltage applications like inverters in electric cars.

Nice video, Big advantages at GaN over fets is at high current applications such as inverters for auto/motor industry... You missed the point that the reason why they are used in domestic applications is that they allow for smaller inductors due to faster switching therefore miniaturisation...

GaN FETs are not a scam, but sure looks like that the "GaN" power adapter you bought is...

One of the big selling points of GaN chargers as I understand it is also power density. Because we can switch faster, we can use smaller storage components in the DC side. This means that we can end up with a charging brick that is drastically smaller because the Caps can be way smaller.

So, a few things to point out (I play with power electronics for a living. I have a PhD on the topic of series connecting normally on power devices to obtain self balanced high voltage power modules. I now work in China for a state sponsored power electronics research facility, particularly on consumer and data center GaN and SiC applications): 1. GaN FETs are not nearly as expensive as depicted from DigiKey/Mouser. Western distributors are known to add a lot of profit on hard to sell (niche) items like GaN/SiC transistors and FPGAs. The real cost of those things rated for a 65W adapter (130~180mR typ., 600~650V max.) in China is around $1 for Chinese parts (InnoScience, etc.) and $1.5 for Western parts (GaN Systems, etc.). A comparable state of the art Si device will cost you $0.5 for Chinese parts (Wayon WMZ26N65C4) and $1 for Western parts (Infineon IPL60R185C7). 2. Transphorm makes D-mode GaN, which is normally on. They have a reliability advantage due to the lack of atom-thin gate structure, so they are commonly used in automotive applications and military RF applications. For consumer stuff, E-mode is more commonly used due to it being normally off. To make a D-mode device normally off, you need to series connect a low voltage Si MOSFET, so when the MOSFET is off, the drain potential of the Si MOSFET (which is tied to the source of the GaN HEMT) is pulled high, since the gate of the GaN is tied to the source of the Si MOSFET, the GaN sees a negative voltage on its gate with respect to its source, so it turns off. So what you are measuring is actually the input characteristics of the Si MOSFET, not the GaN. 3. Gate charge determines how easily and efficiently the FET is driven, not how it outputs (for most high voltage applications, Qout is much more important than Qin due to much higher Vds than Vgs). For GaN, the output figure of merit number does not look good, even for E-mode devices. Only in very few applications like QR flyback GaN has a marginally advantage compared with Si, and even that is mostly for marketing reasons. For most applications, rest of being able to be driven faster and switch faster (which can be done equally well with well designed Si drivers, anyway you are limited by EMI regulations), they do not possess a much better performance compared with Si. 3.1: A few months back I did a round up of power FETs, I tested saturation current to output capacitance@100V ratio at a few given Vds, Vgs and Tj of a few top Si super junction MOSFETs (Infineon, Wayon, Toshiba, ANHI) and a few GaN E-mode HEMTs (InnoScience, GaN Systems) of similar voltage ratings. It turns out GaN has not only no advantages to those top Si MOSFETs, they lack by a huge margin. 4. About reverse recovery, E-mode GaN does not have a reverse recovery charge, but they have horribly high Vf in third quadrant freewheeling mode, some 3V~4V. Cascade D-mode GaN does have a reverse recovery charge from the series connected Si MOSFET body diode. This can be alleviated by parallel connecting a low voltage Schottky diode with the MOSFET, but so far I've not seen this being done, probably for patent reasons. Cascade devices do have lower freewheeling Vf due to the GaN is in conduction mode (since there can't be a gate bias voltage from nowhere and they are normally on), the only Vf (other than Rdson*If) comes from the body diode of the Si MOSFET. 5. Some of the smallest and densest chargers are Si, like the Delta Innergie 60C. The biggest reason why GaN is massively used in chargers is because Xiaomi invested in a large portion of Navitas and Xiaomi wants Navitas to bloom, so Xiaomi used its consumer electronics market dominance to drive the market towards GaN. When other companies see this novelty marketing makes money, they so the same, that's what landed the market now what it is. 6. This website (www.chongdiantou.com) is probably the world's largest charger teardown database. When in doubt about a charger, search here. It is only offered in Chinese, but you only need to see the pictures, not the marketing verbiage. References: 1. My visits to suppliers. 2. Trahsphorm website, VisIC website. 3. Trahsphorm website, VisIC website and USCi website. 3.1. drive.google.com/file/d/1HD702LLCCjSAPlnAypknSWk10G7jkWs5/view?usp=sharing 4. EPC, GaN Systems and Transphorm datasheets. 5. Innergie kickstarter page and some market research reports. 6. The website itself.

I love the crossover between material sciences and electronics! Thank you for the video!

I always find myself so in awe of your clear, square drawing skills

It's newly discovered but amazed to find it these early in device

As a marketing guy (formerly in product development), I need to tell you that the vast majority of consumers want a low purchase price in combination with big brand name, giving them status amongst their peers. A smaller group wants good specs (on paper) - so they can justify the purchase. Only a small minority has the mental horsepower to separate important features from marketing fluff and eye candy and will base purchasing decisions on validated performance.

What I like about GaN the most is the size. Getting a 65w GaN charger is much smaller than a silicon one. One company even makes a 20w GaN charger in the same space as Apple's old 5w charger.

I also tested Baseus 65W GaN-PS in my lab. @ 240V AC, it made 68W and @ 120V AC it made the promised 65 W by getting pretty hot, but still reliable! Nice product --> using it every single day.

It’s really awesome that the chargers are now much smaller at same power. 100w bricks aren’t that bulky anymore. That’s the main difference that gan tech makes.

The moral of the story is: Don't pay more for a GaN adapter because they'll probably lie to you and send you a silicon one anyway!

I love watching your videos!!! I don't half to open my own stuff to see whats inside!!!

oh yes, melted oscilloscope probes, now that is the sign of prototyping.

I'd be interested to see GaN being used for other circuits, like ESCs, and if it has significant differences.

This was amazingly thorough. Thank you!

it feels so good whenever I see your video you give a lot of knowledge I listen to all understands a little but in front of my friends I feel like I have learned a lot from your video staying creative and waiting for your video eagerly

Great video, gave a great overview of those for me. For me, the only thing that calls my attention to those gan charger is the size. I guessed that due to less heat produced, they can put it in more compact cases.

Great content as always! I would love to see you testing an induction motor as a generator...

I think one of the main reasons why GaN is still expensive is that the wafer diameters are typically smaller than silicon wafers (4 or 6 inch vs 12 inch). However they have been increasing in recent years, so that that may reduce the cost eventually.

GaNs are definitely not a scam. With GaN, MHz converters are realized decreasing volume of power supplies. I worked on a 1.2kW Power supply with GaN HEMTs, we were able to achieve titanium efficiency because the GaN allowed us to use a bridgeless topology which would have been impossible with silicon FETs.

A think I liked when working with GaN fets was that you could bump up the switching frequencies, which would enable you to run smaller components

The *floating* circuit is missing the explosions that electroboom usually hosts

This is a really nice and informative video. Thank you so much!

Excellent video as usual, many thanks!!

Thank you for making this video. Fantastic content!

The stray inductance that circuit must have been dealing with at the fet gate makes me amazed the fet didn't fail with that crazy ringing before you snubbed it. The snubbing may also be where you were losing efficiency. But that being said, it could imply these GaNFETs are more durable. The lack of the reverse diode effect does unfortunately exclude them from many neat uses of mosfets, like reverse polarity protection.

GaN FETs have been around, mostly in RF since the fast switching speeds help with rise/fall times in pulsed transmissions. It’s interesting to see their applications in improving efficiency in SMPS. Even though the gains in efficiency are less than the increase in cost I will be interested to see their use grow as that cost decreases over time.

Nice to see a video on GaN technology!

Love the whole MOSFET Cinematic Universe ♥️

I like to call you a great teacher. Because you are giving all informations about your project, which are very helpful for us study more.

Excellent video Scott, looks like we're are at 90% efficient for laptop charging though USB-C now :)

Excellent as always. Thank you.

I got a notification to renew my subscription when I open this app. I got a GAN ad when I clicked this video. It's crazy because I watched 100 videos today with no ads now I'm gonna get ads non stop. It sucks because I just skip untill the ad is gone but I miss out on cool videos like yours. Ads are a double edge sward.

Regardless of the technology inside, I'm happy with my new Xiaomi "GaN" charger. I've looked up a teardown (free document on ResearchGate) to see how they fit a 65W PD charger into such a small space, and the engineering is on point!

Hol-up, you forgot to attempt taking off the "GaN FET" from the charger, and the MOSFET from the charger. I want to see you change them to the one you bought and see the improvement.

Nice information. But u have to also compare both at higher frequency, to see of there is any dynamic problems.

Mind Blowing and Awesome information

With those long wires and large loop areas between your components it is clear that you get high voltage spikes when switching off the Transistor due to enormous leakage inductance and high di/dt. With fast switching speeds minimizing leakage inductance in the circuit arrangement is crucial, not only in power electronics.

Also with ganfets you can replace the diode in a buck/boost with a second fet which massively improves efficiency up to 99% in most cases.

Excellent vid as usual ! :)

I love you’re projects

I love your illustrations....

The GaN components are in the ICs for the PD protocol.

I thing GaN is something I’ve probably seen in listings and marketing and just ignored. I’d not even known about it before, but thanks to this video, now I do! Brought up a lot of fun questions for me. Like, why are these so expensive? How are they manufactured? Stuff like that, which I’m going to enjoy looking into and learning about. ☺️

His notes are epic! They should teach his method in school.

I got an ST GaN Power MOSFET advertisement in the middle of your video. 😂 GaN may be better suited for switching frequencies in the MHz to GHz range.

Well, my job is to grow GaN and do research on HEMTs so i am happy to see GaN devices out in the market. They are expensive to make due to complexity and material cost, but they do get cheaper in time... They are essential for RF applications, where they largely outperform Si. But not in everyday electronics.

Nice to see that the industie is shifting to better efficency, but a cost for a single GaN Mosfet is incredible compared to the normal ones

I think the main industry drive for GaN is not the efficiency directly, but the fact that it allows for hight switching frequencies which in turn allow for higher power density converters.

Need more of this in my feed

The largest part of the switching losses in the mosfets is not from charging and discharging the Qg, but the drain-source voltage and current "switching". You use around U*I/2 for the turn on and turn off durations. These durations are ofcourse shorter when the mosfet switches faster, which is possible with a lower Qg.

The snubber you added to the GaN fet is probably needed because of the inductance of the leads, and it will reduce the efficiency by increasing switching time. A slight flaw, but a good instructional video.

I think lifetime cost of ownership (which depends on the cost and lifetime of the device, as well as efficiency) is probably more important for most users. Or perhaps the one that's cheapest to buy, providing it has reviews that say it works okay.

GaN oO defiantly something I need to keep on my radar! Thanks!

Very nice evaluation. I think that if you could arrange a boost converter exploiting GaN body diod then you may increase the efficiency tangibly as Qrr is literally zero in this Mosfet or most of them.

Nice Agilent oscilloscipe, I sure miss using the ones that were by best friends for a few years...

Bought the anker one. Works great

Interesting how I got an GaN PSU Ad right before this video (MasterGaN)

The issue with your circuit is that the parasitics will dominate. With correct layout you should switch much faster. this fast switching means that the inductor can be much smaller and also run at lower flux densities

Great video man you did an even better job than Linus Tech Tips at explaining how GaN works!

Well... It definitely seems like a step up from the traditional FETs... Not by much, but still in the right direction. 😊 I hope we can see much more stuff like that in the future! Thanks a lot for the video, dude!!! Stay safe and creative there! 🖖😊

Great video. You probably know, but I will mention it anyway. The long leads between transistor and other components, seriously increase the inductance, which limits the speed of the transitors, and increases the switching losses. The only good thing it does is limit voltage spikes when switching, but usually these things are done using specialized drivers, with clamping transistors, and so on. Your signal generator probably doesn't have enough peak current to really drive these transistors at 500kHz. Also in some situations you actually want to slow down the switching (i.e. limiting the current to gate), because due to Miller capacitance there might be weird things going on. For simple SMPS this often can be easily mitgated, but for things like inverters it is more tricky.

Very informative video.

I got one from Amazon. Works well and smaller. It is QC 4.0, so that might be a part of it.

I’m guessing the shift from 100mm to 150mm wafers finally made GaN cheap enough to compete here. Never expected this so soon though!

See you next time 😁👍🌹 I like your explanations

Thank you for video.

Great video! I was skeptical when I first saw GaN chargers. I didn't doubt the tech, just the companies that advertise using it. Glad to see this is something real and tangible for mass production unlike "X college students discover Y battery tech to charge an electric car in 2 seconds!!!!", However, it's still crazy to see your product was actually missing the component it needed. You should take a closer look, I'd love to see if they snuck a small one in for something useless, like driving an LED. Thanks for the info and your investigation!

I was interested in the selection you made for the most desirable feature. I would agree that efficiency is key in certain circumstances, but for me saving electricity on my bills isn't something I'd worry about for these types of devices. Dealing with the heat generated is a far higher priority for many of my projects. Having lower internal resistance generates less heat, and therefore facilitates higher circuit power capability before things roast, and/or smaller heatsink requirements, or just as much bang from a physicaly smaller device. The difference in terms of cost is pretty fierce, however, so not a technology that would be my go-to without some pretty special circumstances. Great vid' though. I've not seen this GaN tech in the wild myself, but it's useful to know what's out there and definitely useful to have a real world view on the technology merits away from the obligatory marketing shpeal that accompanies so many gadgets. Thank you 👍

i love your videos. thank you

As someone working in this area, I have my doubts about GaN. SiC gives you about the same performance, but better reliability, as GaN has poor thermal characteristics and can't handle transient overpower as well as SiC (which can basically be considered to work the same as silicon; it doesn't need the same special care that GaN does). I'm not sure how the price compares, but I'm pretty sure they're on the same order of magnitude.

@GreatScott! Thanks for your studies of GaN. From your measurements, and your research, do you have any explanation why your first efficiency measurements @4:28 showed the older MOSFET supply being more efficient at lower voltages, while the "GaN"-labeled new supply did better at higher voltages ?

I got an ad from ST Microelectronics about their GaN technology on this video. 2% power loss difference isn't much, but with the amount of energy we use every year, that could save so much money and lower the amount of CO2 from energy plants.

Excellent!

I have the GaN 65w Ravpower charger, it's great for my laptop. Like 1/4 the size of the brick that came with my laptop but charges same speed/maybe faster

You can compare two different mosfets an find much larger differences. A designer will select the best component fitting a budget and GaN at this prices will likely never be the choice. Even if cost is not a factor at all you can still find better mosfets at least based on last time I looked.

Could you do a project on a DIY car alarm since you did one for the motorcycles? Perhaps one with a key fob.

I don’t quite agree that a consumer values the efficiency most (especially with these low values), but I might be a different consumer. I am more interested in seeing that it actually can output 65w.

here's what I think though, efficiency is not the primary concern for most consumers. what I think most people wants is: - First, a smaller charger that can output more so their phone can charge faster depending on what standards it used, and light to carry around when needed. - Second is safety, so that their phones don't puff out some magic smoke while charging. what GaN promises is smaller charger with higher and more stable output compared to traditional silicon mosfets. So yeah, less chonky 200W laptop chargers (which is currently about the size of a brick with traditional silicon) is what consumer wants. not laptop charger that has 99% efficiency and still chonky asf. So yeah, great video overall, shame it starts with the wrong assumption regarding the consumer market.

Indeed very interesting ! I guess it's about time you start designing your own ! Another DIY or BUY... ?!

Again, usefull video!

It would be interesting if you could add to the comparison eGaNs. The GaN you tested is a cascode GaN, a hybrid combination of a low voltage Si MOSFET + Normally ON GaN. MOSFET drivers are usually compatible with cascode GaNs (because of the low voltage Si MOSFET at the input), but not with eGaNs (Vgsmax~7V). AFAIK, eGaNs are more efficient and switch faster than cascode GaNs, but because of their very low Vgs-threshold (~1.5V) and low gate capacitance, you can fry them easily due to voltage spikes and false turn-on.

You are the best!

This is reminiscent of the "graphene" power banks. They just add a new buzzword as a sales gimmick. I'm not sure I'm comfortable with the promise of hundreds of watts of power in tiny plug-top PSUs. The words "bang" and "skidmark" come to mind.

Beautiful representation

Regarding efficiency - One should also take into account lower power to drive the gate of the GaN vs MOSFET as GaN capacitance tend to be smaller. Also, this advantage of GaN FETs can be traded into higher operation frequency - smaller magnetics and capacitors. However, to fully explore GaN advantages in high speed circuits e.g. pulsed laser drivers, one needs review their packaging (contact me if interested).

The add i got at the beginning of this video was about GaN chips. First time I heard of it. Hilarious

The most amazing feature of GaN MOSFETs is their capability of exploding if overcurrent happens. Even if they sometimes are not needed, that makes using them worth it (at least for the engineers that need to test the prototype)

Lol I was just wondering what's up with these chargers and searched RU-vid but I didn't expected that you made I video on it, I should enable the notifications 😅

What I miss in this video is the heat GAN can handle. I read somewhere (sorry don't have the source) that GAN can handle higher temperatures and this feature helps to build smaller power supplies. I have four GAN power supplies and they are all smaller. But they also feel hotter.

The problem I have with switch mode power supplies is that many skip out a noise filtering, this can be a problem with audio gear and even bigger problem with SDR.

Did you try those small Anker ones. Do they deliver the same power while being that much smaller? Kinda curious since you said GaN is less efficient at 5V.