That's important for switching power supplies, especially small ones. A switching power supply is always a few milliseconds from being a short circuit across the input. And FETs fail in the ON state. That's why those things are inherently fire risks and need protection circuitry. Really tiny ones make it worse; if they fail, there's not much space to dissipate heat before something blows and opens the circuit.
Ugh. I ordered the four-port one they mentioned without considering it might not have UL approval. I'll be looking for the symbol when it comes now. Thanks for bringing it up.
If the thing works as advertised and is safe, it's amazingly useful. It should quickly charge absolutely every device I have except my work 2015 MacBook Pro (that I'll likely replace soon), and up to for of them at once. (Eg laptop, phone, battery pack, and wireless headphones simultaneously.) Handle US or EU input. And be very compact.
I’ve had the slim 45W RavPower one since June and it’s great. It’s almost startling how small it is. I much prefer it in the bag for coffee shop trips, etc. I use it with my 15” MBP and I haven’t seen any power issues with plenty of Chrome tabs and InDesign/Photoshop running. I usually have the extension cord on the 87W one at home—it’s so nice not to have to lug that whole assembly or look for the smaller attachment.
I mean, when it works it will work. When it fails ... you'll be depending on the protection circuitry in your laptop. If it goes catastrophic/worst-case, your laptop might be exposed to mains power.
One time it happened in Australia, who investigated the cause thoroughly:
> We know absolutely that the charger itself failed, and that it arced between the 240 volt input and the five volt output. So that's definitive," said Lynelle Collins of NSW Fair Trading. "We've got photos, we've got proof that's been dismantled, so we know that the charger failed.
My Anker PowerPort Atom PD 4 arrived today. It doesn't have a UL logo, but it does have CE and TUV ones. Are those equally rigorous? There are some other logos I don't recognize; picture:
I'm on the fence about keeping this thing. Besides the safety question, it's a little disappointing that charging a USB-C phone will drop a USB-C laptop's power straight from 100W to 50W. That's quite a step; I wish it could do something like 85W + 15W. When you use all four ports, the laptop only gets 38W, even if the others actually take almost no power. I think their claimed "intelligent power allocation" is overselling it a bit.
Looks like one of the reviews on Anker's product page (titled "Versatile, depending on what you plug in") says exactly what combinations are possible:
That might be a Japanese-market device in the photo? I see a PSE mark from TUV SUD and a Japanese importer name. Having a WEEE bin but no CE mark seems odd though.
I have the RAVPower 61W GaN USB-C charger for my backpack. No UL, but no noise and no issues. It's currently five stars on Amazon, for whatever that's worth. https://www.amazon.com/dp/B07TC53ZYD/
the question is what you're basing this assumption on. Fake Apple chargers also "seem really good" until they blow up or are disassembled to unveil the obvious electrical issues.
Plus its free to make an account and search the UL database[1]. I work in the fire industry and I have to prove to customers all the time that the UL stamp on devices and datasheets is actually backed up with proper documentation.
But if it's a counterfeit product masquerading as a brand name, the fact that the genuine brand-name product is listed offers only false assurance to the buyer of the counterfeit.
When I got a new laptop this summer I researched what chargers were out there, as I was fed up with carrying the normal assortment of cables and chargers. I settled for another GaN charger - the Innergie Powergear 60c[0] which is a very decent size for 60w and not having a mains lead built into it (still very common on non-mac chargers) makes it a lot more compact.
I travel a lot, often with more than one laptop, so now I'm very happy I can charge all my electronics with this one charger and also with the changeable country tips it's more compact than a travel adaptor.
The only downside I've had with it is the US power tip got bent the first time I used it - I contacted Innergie to see if I could get a replacement, but they never got back to me.
US plug prongs can usually survive being bent and re-bent a number of times.
It's quite quite common for people to manage to bend the prongs on their vacuum cleaner dozens of times. Those pull more amps than almost anything else you plug in regularly, and they do just fine. Just go slow.
I've been known to twist them with a pair of pliers into the shape required to plug into Australian sockets (like this: \ / ), then twist them back again.
FWIW, I've had a kind of opposite need in the past (using European plugs while in the US) and I found that the European plugs can be connected to a partially retracted (but still connected) American plug. The inner distance of the two European leads just fits over the outer distance of the two partially exposed US leads.
I mean, since this thread doesn't seem too picky about fire safety anyways... ;)
Yea I had some speakers pop using a US-AU adapter. Luckily it had a fuse I could easily replace. I tried it out with a step-down and luckily it still worked. It got stolen during a break-in a few months later. They didn't steal the step-down. I hope it blows up in their faces.
I've got the same one, very pricey, but amazing to travel with compared to the giant macbook charger. It's only 60W but charges almost as fast as the 87W one for 15" macbooks. It's also really nice to be able to charge all my travel gadgets with one small charger, reducing the number of cables and chargers I have to carry.
I'm hoping that giant power bricks and those adapters that power via barrel plugs will disappear soon, as I find them to be unwieldy and dirt magnets. Computer monitors are most guilty of having some of the biggest power bricks, and I'd love to see them replaced with regular power cables (the ones that plug into desktop computers), or the monitor be powered over usb-c so any regular 100W usb-c adapter can power them.
> Computer monitors are most guilty of having some of the biggest power bricks, and I'd love to see them replaced with regular power cables
Dell Monitors have a single power cable (for example this P2418D [1]). Many other manufacturers ship giant power bricks because it allows them to make the screen thinner, and nobody sees the power brick under the table. It comes down to customer preference.
> I'm hoping that giant power bricks and those adapters that power via barrel plugs will disappear soon
Laptop makers will never let that happen. My partner and I have had 4 USB-C laptops between us for work from Dell and Lenovo and the Dell 90w USB-C Dock PSU is the only one that could power all 4 of them. Each one complained or refused to boot if a different charger was used. The wattages for all of their supplied chargers were different.
If you don't need 60W, I find that the CA4-Pro [0] is great – it has the travel adapter built in (so you don't have to carry attachments), it can act as a travel adapter for plugs for other appliances, and it's got three USB-A ports as well.
I'd love to replace my MacBook Pro's power brick with a small wall charger.
But I'd want a long (10 feet) USB cable for those places where the outlet isn't near where I sit, and it doesn't look like that exists yet. All the ones I find on Amazon are 3A, and the MacBook Pro apparently needs 4.3A.
Thanks. "Current unavailable". I found a few other ones (like [1]) just now by searching for 5A, but I have to say I'm skeptical of Chinese no-name cables that haven't been certified.
I love how no one is talking about how this article is from January of this year... Anker has a newer version that is even smaller now. It may only be 18W and rated for phones, but it matches the size of the original 5W Apple charger. https://smile.amazon.com/dp/B07WRKXQ8W
I've had an older Mu for some time for travelling. There are much cheaper copies, and alternative designs, these days* but I can't vouch for their quality as I've never used them. The Mu seems well-built and after many uses still feels solid.
One of my minor goals for 2020 is to switch all the gear I carry around to being USB-C PD. I've been doing some research on the subject, so just thought I'd throw my 2 cents in (some of this stuff mentioned in other comments).
I started off the year with an Innergie 60C, which has worked great for everything I've thrown at it and is tiny (55mL volume, 88g, 60W USB-C PD). It was on-sale recently, but even at full price has been worth it for me. (Although the newer RavPower PD Pioneer 61W is a good alternative that's almost as small and 1/3 the price.)
Instead of the Anker PD1 18W, for a small charger, I use the Anker PIQ 30W - it's very slim, which actually makes it much easier to carry around. Also, the IMO folding plugs (and extra juice) are definitely worth the extra volume.
Recently, for my Mavic Pro 2, I just got a cheap Cablcc USB-C to Plug Receptacle Charger cable and a RCGEEK car charger that seems to work well as a nice 2-in-1 (it only saves a tiny bit of volume and weight over the wall charging but it also provides car charging).
Also, although I'm unsure of how often I'll need it, I got a 100Wh Zendure Super Tank power bank (which provides USB-C PD 100W charging), since it was discounted heavily for Black Friday (it was only $100 on sale vs $200+ for other similar options).
Also, I travel internationally a lot, and the MOGICS Donut has been my go-to combination power strip and adapter - it's the best/most compact device I've found (and has 2 USB-A chargers built in to handly legacy devices). https://www.mogics.com/3824-2
I have a bunch of USB-C devices - two laptops, a Switch, a phone, and a pair of headphones. The only one that I regularly charge from a USB-C PD port is the larger laptop. The rest do just fine with USB-A to USB-C cables from a four-port (one PD plus three USB-A) adapter. Occasionally I'll pull out my Atom and corresponding cable to charge another one of those devices more quickly, but that's actually pretty rare and I never need more PD ports than that. Never, and I travel more than most. I wish more people knew that A-to-C cables are a totally sufficient, cheaper, and more compact alternative for many devices.
Of course, it depends how much juice your A-ports can provide and how fussy you are about things charging as fast as they can. If most of your A ports provide no more than 1-or-2 amps, maybe 3, at 5V then most (all?) devices that charge via USB-C will charge slower than they could. That won't realistically matter at all for refreshing a phone overnight, or even a chunky laptop, but it'll still matters to some.
I recommend the RavPower 61W GaN over Innergie. The Innergie is smaller, but it is 3x the cost and, in my experience, less reliable and less ergonomic.
I purchased the Innergie after a previous travel charger failed. Loved it at first, but started experiencing issues pretty quickly. The first issue I encountered was that the plug would fold in frequently while I was trying to plug into outlet. Over the course of a couple months, I started seeing more issues with the reliability of the charger as well. It never completely failed, but I would often have to play around with reversing the cable and the direction of the outlet side usb-c in order to get charging to start. This was a bit concerning to me given that complaint USB-C cables are completely bi-directional.
That is not smaller than an Atom PD1. The Atom is 1.61 x 1.37 x 1.50 in. This is 1.18 (x 1.18) x 2.36. The shorter dimensions don't matter because both approximate the outlet dimensions, but the Innergie will stick out nearly 50% further. Also, 88g vs. 59g. Not smaller by any reasonable definition.
As it happens, I have the Atom. Yes, it's true that it can barely keep up with my MBP while in use, but that's not how I use it. It's fantastic as a more convenient option overnight, or as a second charger for my phone, my Switch, etc. I already have a bigger four-port, and any single-port can only be an adjunct to that, so a single-port that can do 60W adds no value. I suspect people in situations similar to mine far outnumber those for whom a single 60W port would suffice.
I have both PD1 and RavPower 61w. Tried carrying just the PD1 for a while, but got caught twice with zero power and took ~15 mins before I could boot my MBP. If you use any heavy power apps (Chrome, xCode) it drains faster than it charges. Both are great for their size, but I'd recommend the RavPower for any laptop use cases; it's only a little bigger.
I just bought one of these a few days ago. It's small and light, definitely an improvement over most power bricks but it's only a little smaller than my wife's MacBook Air charger
I just got a new 16" MacBook Pro and the power brick is 96W, but the same size as the 60W from a few years ago. I'd say this is likely a GaN unit, but I don't have any proof of that.
Well no, it is not, [1] is the world smallest 100W Charger with GaN and 4 Ports. And it is even smaller than the 61W MBP Charger with 1 Port.
And the link to my previous question's answer [2] from an electrical engineer. I will paste it here as well.
Cost, and the fact that it doesn't actually buy you much. I've evaluated GaN for a couple recent designs I've been involved in and found that its benefits simply didn't justify its costs.
What GaN actually does is, mainly, decrease switching losses. That means switching frequency can go up, or efficiency, or power density. These are all good things, to be sure, but the magnitude of improvement GaN brings to most designs is simply not large enough to justify the cost of the parts and the increased design attention needed to use them. (They're fussy little things.)
That said, I'm bullish on GaN in the medium-term. There are some cool tricks that are infeasible or impossible without them, and they really are better in a lot of ways. It'll just take a while for them to trickle downmarket, and even still they're not going to be replacing Si FETs anytime soon. (Part of the lag in GaN adoption is simply that Si FETs have gotten really, really good.)
Yes, size is the main product-level advantage of GaN. But it only lets some of the system shrink; for something like a mains charger, you still need the isolation magnetics, so your overall size is still constrained. And at the power levels of a few watts that many chargers work with, Si FETs are simply good enough. A 5W USB charger isn't going to get any smaller with GaN. It only starts to get interesting with really high power densities.
Ironically, the best USB-C charger for something like a phone (laptops come with chargers, anyway) I've found is simply the Raspberry Pi 4 USB-C charger - very cheap ($10), small, plenty power (15W), fixed cable and no fucking blue Anker LED that can illuminate your bedroom.
You know, I thought that until I started to test it.
I have a Kill-A-Watt for rough measurements and the pi4 charger is slower than my GPD Pocket or ipad pro charger. It does pull 14W or so sometimes, but there's a big limiting factor, it's only 5V. The ipad charger does 5V/9V on USB-PD and the pocket does 5V/9V/12V. So if the cable wears at all, you won't be getting the full rated power due to voltage drop. It's like trying to use a plastic mixer straw to drink a beverage vs a regular one.
I already have a portapow meter for measuring USB-A stuff including watching quickcharge 2.0 stuff boost the voltage on the line. Proper USB-C meter/tester comes this week, then I intend to writeup findings on cables/chargers.
For your bedroom you'd really want an old 5W charger. Why turbo charge and put permanent strain on your battery when anything that takes 6+ hours will do.
For battery lifetime -- also charging to lower voltage and stopping discharging at higher voltage. Cathode will stay intact longer this way and metallic lithium has less chance on plating the anode.
A phone will charge as rapidly as it can without undue risk to the battery's longevity. But, it's still a trade-off. If you charged slower, you would decrease risk to longevity.
But when you to bed, your phone doesn't know that rapid charging convenience doesn't matter. So it will still make the same trade-off. If you use a less-powerful charger, you can force it to take its time in charging.
While charging circuits are much smarter now, and the difference might be minimal, you want lower charging currents to minimize the amount of damage that is done to the materials in the battery. It is universal that higher charge rates cause more damage to the crystal structure that holds the lithium ions.
Does this mean using one of the bigger brick 15in MacBook Pro charger on a 11in MacBook (both USB c) is bad for the smaller MacBooks charger? My gf always uses mind when she can’t find hers...
My preferred alternative to electrical tape is a piece of aluminum foil stuck on with painter's masking tape. Aluminum foil (or any metal) is really excellent at blocking all the light, and painter's tape doesn't leave residue.
I used to run a Dell UltraSharp 3008WFP. A great monitor for the time, but the power LED was so damn bright that black electrical tape didn't fully extinguish it.
The official Google charger (18W) is good, albeit about double the price. It's one of very few wall chargers that will power a FLIR Duo Pro camera without it boot looping. It's very picky about voltage and conks out if there's any droop. Most of Anker's products don't work, though some of the power banks are fine.
I use a dark, but not black, colored electrical tape to kill the brightness of any leds in my bedroom, or that I take with me when I travel. Black will kill the light entirely, but other colors will permit you to see the state of the led underneath.
I'm still waiting for a USB-C charger with more than two ports. Until then, I'm sticking with USB-A cables for everything except my MacBook Pro. For travel (where outlets are often at a premium), I use a four port USB-A charger on a nightstand to charge 2 iPhones and an Apple Watch (this one: https://www.amazon.com/Anker-Charger-Foldable-PowerPort-Sams...).
Had forgotten about that. I worked at the Rockwell science center at that time and went into their clean room once and had to put on a “bunny suit” to work on some computers inside it. They had a gallium chip product of some sort.
SiC has 4x better thermal conductivity than GaN. Operating temperature and breakdown voltage are also higher. You can buy 1.2kV SiC transistors right now, GaN on Si maxes out around 600V. High temperature/high voltage/high power will remain SiC territory for now.
Faster switching speed for the equivalent breakdown, at least from an RF amplifier perspective. SiC was an interim until GaN was developed, and is essentially obsoleted now.
What’s interesting is how the DOD heavily invested in GaN technology in 90s and 00s, pushing the USA ahead of Japan in compound semiconductor. Weather that lead will stay; who knows. The Chinese have a GaN fab now. GaN is critical for RADAR and higher power SATCOM, so big defense support that has dual use for civilian wireless comms.
> Faster switching speed for the equivalent breakdown, at least from an RF amplifier perspective. SiC was an interim until GaN was developed, and is essentially obsoleted now.
Wait wait wait... GaN and SiC have very, very different use profiles, and characteristics. SiC is by no means obsolete, and nor are purpose made silicon switches.
SiC is here to stay because of one very unique trait among all other semiconductors - a very pronounced negative temperature coefficient, and without extreme non-linearity.
Second to that is more or less linear threshold voltage temperature coefficient. GaN has positive threshold voltage temperature coefficient.
Third, SiC can simply operate at higher temperatures, and have known longer lifespan. GaN's current limits are WAY lower.
Fourth, transfer characteristic... Si, GaN, and SiC are all very different. This is one of few measures on which plain silicon beats contenders.
I was thinking in terms of RF amps. Cree was making SiC FETs several years ago, but I think it’s all GaN on SiC now. There was a SiC fab in CA making RF parts, but I think they went belly-up. All the SiC FETs topped out a 2.5 GHz.
How does the negative temp coefficient help; stability for very high temps? I know the positive temp coefficient was an issue in RF BJT, requiring ballast resistors for stabilization, but those are not needed in any FETs. The positive temp coefficient should be useful for GaN as long as you have temp stabilization in the bias network; all of my amps did.
Good point about the high temp. I know of some oil drill electronics in SiC. I just though SiC was dead for RF.
> How does the negative temp coefficient help; stability for very high temps?
You can put multiple switches in parallel, and have them self balance without resorting to active temperature compensation which is completely out of question for any consumer grade device.
For power electronics, GaN is nowhere near as big of a bang as SiC, with its current handling being the primary showstopper. SiC can switch 100A loads at one kilovolt and above with ease, and at very high frequencies. There are simply no equivalent GaN part for this comparison.
Second to that, GaN needs a tricky gate driver, and is normally an
n-channel depletion mode device. SiC can still be driven driverless at lo
Second to that, SiC JFETs still have niche uses in audio amps exactly because of their "bad" shallow IV curve.
Still waiting for the next generation of USB-C hubs. Currently, almost all cause Wi-Fi issues, most will have Windows complain about "limited display connection".
That’s just due to cost cutting (poor shielding). GaN will allow a faster slew rate (higher break down voltage), so emissions will actually become worse.
The FCC needs to enforce emissions regulations. I remember when PCs (even the C64) had cases to meet emissions requirements. Now you see PCs in glass cases. It really sucks doing amateur radio in an urban area due to spectrum pollution.
That depends on where you live, but yes, the design used in the USA (known as the 'type A' connector) was very poorly designed. It gives very little mechanical support.
The country I live in happens to use the type F connector, which is very sturdy.
Incorrectly wired outlets do occur even in the US, so it seems like it's safer to take that possibility into account and just design the whole system to allow them to be interchanged (e.g. make power switches open/close both lines)
On appliances with a physical on-off switch, it's best to have the switch as close as possible to the cable, and on the 'hot' side. If there's a fault (wire touching the metal case) then the appliance is still safe with the switch 'off'.
Nowadays, I think everything would have double-pole switches anyway.
Perhaps it isn't common, but my experience with the sockets in Belgium was scary to me because there were two outlets embedded in a recess quite close to each other. Close enough I was afraid I'd shock myself trying to get a good grip on my plug and pull it out.
Electrically I don't see how that works since there's no interruption of the metal pin inserted into the socket like you see on a tip/ring headphone plug. Unless there's a mechanical process that energizes the live side of the inserted plug after a certain depth?
That's odd. Could you describe it better since there is basically no way one would be under risk of getting a shock on a Schuko or Europlug without inserting a needle or something similar into the holes of the outlet.
We're just talking about two copper-lined holes next to each other for each power connection. There were two of those spaced closely together in a recess in the wall. They were close enough I could have touched the metal of one outlet while grabbing onto the power plug inserted into the other outlet. Since my power plug adapter is two copper-plated pins that mated with the holes and had no electrical break like you see on a tip/ring headphone jack I assume the exposed metal is live and the pin is live when inserted.
Perhaps there's a hidden mechanism that enables power after insertion? There was no switch for each outlet. I no longer remember if there was a switch for the pair of them but I don't think so as I was worried about getting shocked. This was in a Belgian hotel I visited a few years ago. Sorry I didn't take a picture.
I have the feeling that you are talking about european style socket with shallower than normal recess, ie. CEE 7/1. These sockets are sometimes used in Benelux countries for RCD protected circuits without PE, and should only be used for Class II devices which usually have CEE 7/16 “EuroPlug” with isolation sleeves and thus there is nothing to touch. On the other hand nothing prevents you from plugging essentially any other european plug in there which then becomes safety issue both because of the exposed live pins when (un)plugging and missing grounding. Similar sockets were (are?) also used in Russia.
This is probably the only case when CEE-style socket is not designed such that it is safe to use with any CEE-style plug that mechanically fits. In general I view the system as better design than BS 1363, because it solves the relevant safety issuess without overengineering and with reasonable degree of backward compatibility.
To me that reads like an article written by someone trying really hard to defend the U.K. electrical system. UK receptacles and plugs have complex safety features mostly because the UK electrical system is awful. The UK (historically at least) used ring circuits that are fused too high such that an inappropriate resistive load that will not blow the fuse can still overheat the wiring. Hence more fuses than should be needed to partially mitigate the problem.
Modern US receptacles are “tamper resistant” and are required by code in places that kids can get to, and they have similar safety shutters. Unfortunately, many of them, especially the cheaper ones, suck and actively eject plugs.
The lack of insulation on US plugs to prevent shock when plugging and unplugging is a fair criticism. I suspect this is mostly because US prongs are thin and could become too weak if the metal were narrowed to make room for insulation.
??? The UK plug is gargantuan and unwieldy, and the inbuilt fuse a pointless anachronism grandfathered in via historical momentum. The Euro plug is better in every way.
Did I understand correctly that outlets contain a switch and are off by default and that the grounding pin switches them on when inserting the plug? That's great.
Which means you can use a European plug in a UK socket, if you first put something in the earth slot (a key works well).
European travellers are generally impressed when I show them this trick, and sometimes rightly concerned that I'm sticking metal objects into a power outlet. If there's any chance the outlet is wired incorrectly, don't do this unless you can isolate the outlet or the key.
Yeah I wouldn't rely on things being wired correctly. When I moved into my current UK house the neutral and earth were physically connected (someone had driven a nail through a cable and "got lucky"). Took a while to find the nail and fix that.
UK is probably the safest but it’s also bulky and presents an unlikely kind of danger: it tends to lay with the pins upward when on the floor which is deadly when stepping on them in the dark.
European plugs IMO have the right balance between safety and size, with the bonus that they don’t stab your feet if you step on them.
> UK is probably the safest but it’s also bulky and presents an unlikely kind of danger: it tends to lay with the pins upward when on the floor which is deadly when stepping on them in the dark.
> It’s a truly brilliant design. The only caveat is that, as with Lego, the rugged, bottom-heavy design of a U.K. plug makes it an almost scientifically perfect caltrop.
True but I have to say the combination of UK plug adapter mated with a US power strip is extremely convenient. Particularly since modern UK outlets all have individual switches which comes in handy when you don't want a snap and a spark plugging something into the power strip. :-)
Ok, but they're USB-C, meaning there is an 80% chance they implement the spec incorrectly (resulting in weird issues with random devices), and a 10% chance that they are straight up unsafe. Benson is no longer updating his list AFAIK, but that's not because people have learned to do USB-C correctly; they haven't, e.g. [0]
GaN has a higher breakdown voltage than Si, and a higher drift velocity, which allows a faster switching speed (for the equivalent bias).
For power supplies and switched mode RF amplifiers, you need to switch the transistor on and off as fast as possible; ideally an open or short circuit. During the time is is transitioning from on to off, it is dissipating power, thus losing efficiency in your circuit.
If you can operate at a higher bias, your passive support circuitry can operate at a lower current (lower I^2*R losses) not to mention smaller due to higher frequency (smaller inductors and capacitors).
The faster switching also generates more harmonics, which can align in phase to cause higher voltage transients, thus you need a higher breakdown.
The issue with GaN is fabricating it. It is a compound semiconductor grown with epitaxy (layer by layer) and has to be lattice matched to a carrier substrate, unlike Si which is diffusion doped into the bulk Si substrate. So GaN is maybe at 8” wafers while Si is much bigger. Some GaN is on Si carrier (cheaper but lower thermal conductivity) and some in SiC (expensive but better thermal conductivity). The goal is to grow it on diamond, but again the lattice matching is a problem.
The longer term goal is diamond semiconductors. Maybe 30 years from now that will replace GaN, as GaN is doing to GaAs and Si for certain applications.
Basically, GaN has less electric resistance than silicon. They generate less heat when used in high voltage (or amperage, depending on your viewpoint) applications.
We can't make GaN transistors nearly as small as we can make silicon ones, but transformers/chargers don't need many transistors in them, so it's fine.
It's fantastic for travel. It can charge my laptop (USB-C), Apple Watch + iPhone (USB-A) and power bank (USB-C) all at the same time. It also has a detachable AC cable so you can swap it before you leave instead of carrying an international plug adapter.
A man in OEM manufacturing here. Not an electronics engineer professionally, but more or less involuntary having to deal with it.
First, I will say that GaN is not a make or break deal yet now. There are very high performance silicon switches that can produce equal gains for use cases in consumer electronic. In absolute comparison GaN is of course winning over Si, but use case wise, not so much.
GaN's main appeal is that you can retrofit it into simplest buck topologies, and get instant gains without any extra hassle.
GaN works best for low current, low voltage applications you normally see in consumer electronics. Everywhere else besides RF, it's not a clear improvement over silicon.
For long time GaN existed in a narrow niche of high frequency circuits, where people were OK with n channel depletion mode device with a lot of tricky sides. Its use as a power switch is relatively novel.
Enhancement mode devices are now on the market, but there is a catch. Because p-GaN is nowhere near as good as n-GaN, pure GaN enhancement mode devices are nowhere near as good as depletion mode devices. For this reason, some companies are trying a an approach with hybridised GaN-Si device to overcome that. Again, that is way more tricky and expensive than a single material device.
Now, back to chargers. It is easily possible to make more compact chargers without any exotic switches GaNfets included for as long as you put just a little bit more brains to engineering by going to better topologies.
What a lot of charger makers do these days to go along with the trend for smaller chargers is to turn up their switching frequencies as much as possible without melting the charger. They still do miscalculations about that, and you now have a lot of molten/burnt chargers as a result.
They are being misguided by the switching speed narrative, and completely miss that point that size of passive components has to do with way more things than just switching speed.
First, they can throw away the standalone rectification, gaining some efficiency in the process. Second, they should either go with some advanced flat transformer setup with appropriate resonant topology. Or they can throw away transformer altogether and use piezo transformer, or capacitive isolation. Third, a separate buck for last stage DC-DC can also be thrown away if you use multitap transformer and some electronic switching.
Transformers are by far biggest contributors to charger volume, and weight, and are bigger than capacitors in some cases. Throwing them away will provide way more space savings, along with other extraneous components.
So think twice about going the GaN route before considering things above first. Switching performance in a typical AC-DC is by far not the biggest of your problems.
I think GaN transistors are a major thing in the next decade. Designed a GaN FET based small vehicle motor controller few years ago and similar size/speed/efficiency is currently not achievable with any other mass produced transistor type. There used to be only small players on the field (GaN Systems and EPC) but now Panasonic and Infineon have started offering their versions. Expecting the prices to go down and volumes go up.
This is an area we needed Jony Ive to dedicate some time to improving. An Apple Pro charger for road warriors designed by Jony would be an awesome parting gift to the world.
> It’s not perfect yet: Anker’s 30W Atom PD 1 struggles to power something as large as a 13-inch MacBook Pro
Umm wot, maybe older MacBooks, maybe when gaming or rendering. For writing code and browsing on a 15incher I'm averaging 20watts. Cheap 12v cigarette lighter one that does 24w is enough (but barely) to keep things running for me. If I turn off most of apps I get as low 6watts on a hexacore device. I use iStat menus to monitor my power use which is quite exciting.
I am actually considering buying 30W one for it's portability.
But then again I am not a YouTube influencer that occasionally games and cuts videos (you know, the person that Apple designs it's computers nowadays for).
> the person that Apple designs it's computers nowadays for
I develop software in Apple's programming language using Apple's frameworks and Apple's own IDE, and power usage is through the roof. 50W while typing (and auto-complete is doing it's job) and 80W while building.
I think it's odd and quite rude that you dismiss anyone who has higher computing than just typing some basic text and browsing the web to be "a YouTube influencer". If all you need is the computing power of an Eee PC then yeah, I don't think you are Apple's target market.
I use WebStorm and IntelliJ. From what I know Apple's IDE is one of the most appalling one while IntelliJ is one of the best. Yes they are both using quite a bit of resources. Nope, neither of them are compiling code using GPU and via super accurate colour gamut.
Unfortunately, it depends. There are various standards that devices use to negotiate how much power to send over the USB cable. These chargers tend to support all the popular standards so they'll charge your phone at the fastest possible speed (unless you have a OnePlus or OPPO phone). If you have a midrange or higher Android phone, the included charger likely charges at max speed. If you have an iPhone with the 5W adapter, any of these adapters will charge faster than that.
If your device accepts wattage (current? not totally sure about the terminology) higher than your current charger can provide, then yes. Basically, devices will charge at minimum(phone_rate, charger_rate).
Was recently thinking that single pair power over Ethernet could probably handle 90% of the use case for residential power. 50W is enough for a LED/Fluorescent lighting, power a laptop, lighting, charge your phone.
WOW... This is a horribly misleading article and discussion. The silicon of the switching circuit PALES in comparison to the real magic here.
The wattage capability and size of these chargers is only possible because of US “power delivery”. These chargers are NOT hitting 30+ watts at 5V traditional USB voltage. Yes, there is another power and ground wire pair in the cable, but iirc they got smaller in diameter.
These devices are small and cool there because your device can charge at up to 20V now.
GAN didn’t outright make that happen on the source or sink side. It didn’t hurt, it’s cool, but the difference is smaller than they are implying by comparing a 5V device to a 20V device.
An article that goes on about fast charging and never says “20V” once is not telling you the full story.
You can falsify your own argument by checking out the range of PD2 chargers from Anker or RavPower, observing the models with similar wattage and same multi voltages including up to 20V, and then noting the size differences.
They’re not making the new models bigger just for fun.
I know that "silicion" isn't just pure silicon given dopings but I can't help but ponder the environmental and toxicological differences between the two. Gallium nitride seems loke it might be more toxic and gives me a sneaking suspicion they will be a "compact floreacent tube" solution that is a flash in the pan decade standard that gets replaced by something far less toxic anyway (LEDs). However I know that I don't know the details so I cannot judge only raise concerns which I hope were already addressed.
I understand the logistics issues involved in standardization of repeatably used sockets but USB chargers are so very "unhygenic" from a security perspective. Proper design from the data end shouldn't allow any unexpected changes but that is error prone in practice. It is sort of like sharing cups - in theory the immune system should take care of any pathogens but in practice it is a needless risk.
Getting into engineer dreams, an ideal design would involve readily apparent subsets between charge and data pins even if they occupy the same socket. So any charger honeypots to plant or extract data would be obviously untrustworthy.
There's no need to ponder the toxicity of gallium nitride and worry about your "sneaking suspicion" that it's toxic. It's in the "may cause skin irritation" level of toxicity, so really not worth worrying about.
https://www.ltschem.com/msds/GaN.pdf
> Gallium nitride seems like it might be more toxic...
Surely not more toxic than gallium arsenide. The amounts of material involved in a manufactured product are pretty tiny, so the semiconductor material is not hugely concerning.
That's important for switching power supplies, especially small ones. A switching power supply is always a few milliseconds from being a short circuit across the input. And FETs fail in the ON state. That's why those things are inherently fire risks and need protection circuitry. Really tiny ones make it worse; if they fail, there's not much space to dissipate heat before something blows and opens the circuit.