240W USB-C PD chargers are nearly here, says Framework CEO

I eagerly await more reviews of other USB-C PD chargers, e.g the 65W Lenovo ones you can get for pennies on ebay.

I expect the trend to continue as it's likely cheaper to toss in a single USB-C port and controller chip than it is to supply a power brick. I can see most stuff shipping without an actual PSU very soon - I'd estimate 50% of devices already do so these days.

My impression is that most devices with barrel ports don't use that much power and would be fine without USB-PD. They use barrel ports because they were designed before USB-C or because USB-C port is too expensive. I supsect many would be fine with USB-C to USB-A cable and charger.

Lenovo has also gradually been adding USB-PD to their gaming laptops, first at 100W and by now I believe at 140W. Though the one I use can use up to 300W and the only viable aftermarket charger is the SlimQ 240W, which can do either 2x100W PD or a range of barrel plugs (and lenovos high-wattage rectangle) on one relatively small brick.

Right now most devices pick the highest power option (that they can handle). For a variety of reasons, it would be super sweet if we could pick lower power options! Maybe it's a multi-device charger & you want to leave more capacity for other devices. Maybe you want to slow charge your battery to extend it's life.

Almost every usb-pd device can accept lower power options, if plugged into a charger which doesn't offer the maximum rate. The only thing missing today is software, is user control over the power delivery negotiation process. Very very achievable, with minimal effort.

Unfortunately, due to cost or incompetent engineering, most devices only accept either a few charging configurations, often just one.

I didn't realize this as my first laptop with USB-C ports could be charged with any USB charger, even a dumb 5v 500mA phone charger would eventually get the job done over a couple days. I just assumed everything was like this, but unfortunately not. A lot of laptops and cameras will refuse to draw any power at all unless they can negotiate certain configurations.

so even without any software or clever switches to slow-charge your laptop, if you took a USB-PD laptop that prefers a 240W charger and plugged it into your 50W tablet charger or 20W phone charger, it would charge. it would just do it a lot more slowly than witht he high-power charger.

I suspect your lenovo works the same way - if you plugged it into a 65W thinkpad X1 charger, it'd probably slow-charge your laptop.

>> The company says it uses Weltrend WT6676F, ON Semi NCP1622, and JoulWatt JW1556 controllers, as well as GaN switching parts from both GaN Systems and Navitas “peaking at an amazing 93% efficiency” for this 180W adapter. Both those parts and Chicony’s assistance as a power supply manufacturer are obviously there for other companies to use as well.

So likely even less efficiency for the higher rating. I'm very interested to see how they're venting this heat passively.

My current charger of choice is the Anker 747 150 W, 3 usb c (equal capabilities per port of 100 W) and 1 USB A (24 watts) but there have been a lot of other models released since then. Somewhere around ~240 W might be when I look at options again, right now my MacBook won't charge at full speed due to the 100 W limit on the 747.

I think it's also super important that there is now a market of competing products too. Until recently, devices were sort of stuck using whatever the manufacturer provided. Almost no one shopped for power density. Now we have an interoperable standard & different companies can compete to be better.

USB-PD has been pretty epic so far, IMO.

Expensive in terms of cables or connectors?

In both cases, I've been paying considerably less for USB-C (cables and chargers combined) than for proprietary replacement chargers.

> it even works with a 45W adapter

My favorite thing about USB-C charging is that (at least Macbooks) it works even with lowly 5W chargers in a pinch! Sure, it takes more to fully charge a laptop that way – but I can sustain my Macbook Pro's charge with an 18W phone charger on an airplane no problem.

Is it? I’ve been using USB-C Macs since 2017 and I’ve never had any broken ports, despite some significant abuses (cable trips, grime in the port, etc). A few worn out cables, and failed chargers, maybe… but no problems on the laptop itself.

Beyond gaming, the most interesting use cases I have seen and heard are CAD work/displays of highly complex models, creating heavy duty multimedia presentations, game development, and just about anyone in a country that either needs to do a lot of travel or does not have ready access to a high bandwidth connection. I don't know how prevalent those cases are, but they did surprise me a little.

On a more fundamental level, there's the physics of how much power you can pass through a cable/connector safely.

So unless you want to drag around an NEC type cable as thick as one of your fingers, you need to set a limit.

Edit: Fixed math. I haven't had caffeine yet.

Increasing current on the other hand heats stuff up which... is also dangerous

USB cables can only get so thick. And voltages only can get so high to not be dangerous to people.

We didn't want to change the connector. So we are stuck at 5A. But we can raise voltage & still have some margin. So voltage was raised to 48V. 5A * 48V = 240W.

As for raising the voltage more, it's likely very technically feasible, but probably not, for safety reasons. There are various levels of what is considered safe voltages. Higher voltages have higher ability to injure humans, to cause shock or potentially spark. Voltage is a unit of electrical potential, essentially how bad some juice is desperate to get out. 50V is the "Safe Extra Low Voltage" (SELV) limit for AC. It's actually 120V for DC but 48V/50V has a certain dislodgable-for-now mindshare. https://en.wikipedia.org/wiki/Extra-low_voltage

Connectors also have limits to their voltage isolation. If you have 1000V that electric potential really wants to get out & will arc across gaps. If there's debris or a worn connector, the threat of say 200V causing some short is much higher.

We probably could go higher. Usb-pd is super safe. When plugged in, it's in a very limited 5V state. This is a high risk moment in the connection life cycle, as pins are sliding into place, but partially connected & likely not aligned fully yet; not having any real voltage applied at this phase is a colossal design win against so so so many power delivery mechanisms in the world. Device & source _after being connected_ then have to negotiate power, on the secured connection. They ongoingly perform bounds checking to make sure the power is flowing in an expected way & will disconnect if out of spec. The connector has good isolation. 120v * 5a would be 600W and is still SELV. Add some thermal protection to the ports to make sure everything's OK there and it's probably going to just work. But any mishaps (ex: puncturing the cable, debris inside the device causing a short) would be more severe/scary. I'd love for some hackers to find out how high our connectors can go. Maybe in lab conditions we can get a usb-c connector doing a couple hundred volts fine. I would be unsurprised. Being safe for the real world though, after wear, and what happens when there is a fault is why we have SELV. But again, SELV says we could go up to 600W on this connector maybe.

One non-concern should be any additional heat, such as on cables & connectors. Since amps are still only 5A, the power loss is actually the same. Pretty great.

Thus you get 5A @ 48V which is 240W.