Your phone charger and PSU both use a an SMPS circuit, which switches at a very high frequency (tens of kHz), because it is more efficient and can be easily regulated by changing the amount of time the switch is on or off each cycle. (PWM). To switch this fast, they use a transistor. The problem is that while fully on or off, it's either allowing no current through or letting all current through with no resistance, so no heat generated. But it can't go from 0 to infinite resistance instantly, so during the switching it has a resistance value that lets current through, and generates heat. GaN transistors (GaNFETs)do this switching a lot faster, so they generate less heat while switching quickly, thus wasting less power. High-end PSUs however tend to use a circuit called ZVS (Zero-Voltage Switching) with LLC topology. Basically what it means is they have a certain layout of components that resonate with each other, and oscillate the voltage naturally. If you time this correctly with your switching frequency, the power will be off while the transistor is switching. Therefore, you will have almost no power loss due to switching, even though you're using regular transistors. Right now this kind of circuit is either too big, too expensive, not efficient for lower power levels, or a combination of the three to be used for USB chargers, so they use GaNFETs to reduce the switching losses instead. The only place where it might increase efficiency is for the part of the power supply that downconverts the 12V used by most components to 5V and 3.3V. They don't use much power, though, so you will not see huge efficiency increases. Ironically it will probably help most with powering USB devices connected to your PC. Disclaimer: I'm not an expert so I may have some inaccuracies
Why no GaN ATX PSUs? Because GaN is used in chargers primarily for marketing reasons. If top ATX PSU manufacturer used GaN then all smaller manufacturers would say GaN on their products too. Especially Chinese companies (they like to compete with specs, numbers, features).
Silicon is plenty fast enough. 4GHz CPU is silicon. GaN is more expensive so if you’re engineering an ATX PSU, why would you use GaN? If you’re engineering a charger, you have to use GaN somewhere otherwise consumers won’t buy your product because they think GaN is important.
The whole point of switching power supplies is that the AC frequency is very low, so you would need a huge transformer to convert it. Instead of doing that, modern power supplies multiply the frequency by first rectifying and smoothing AC to DC and then using a (GaN) mosfet to create a much-much-much higher frequency AC that can be converted by a tiny transformer, as the video explains.
@@ChargerLABbecause silicon can’t switch fast enough? I don’t believe it. Also, why is a bigger bandgap an advantage? Bigger bandgap is higher voltage drop (equals higher losses).
Synchronous rectification with two transistors and no diode is used in high efficiency circuits. The voltage drop of diodes is not that important now. Or high voltage Schottky SiC diodes can be used. I'm not sure if GaN can build Schottky type diodes.
Good explanation of the use of the technology. I forgot the total size is mostly determined by the transformer. Have you done any videos on switched capacitor converters? I've heard they are what phones use for fast charging now, but I don't understand how they work.
With all the advandage with GaN I'm wondering why we don't still see GaN psu solutions for PCs for the common ATX, TFX, SFX form factors
Your phone charger and PSU both use a an SMPS circuit, which switches at a very high frequency (tens of kHz), because it is more efficient and can be easily regulated by changing the amount of time the switch is on or off each cycle. (PWM). To switch this fast, they use a transistor. The problem is that while fully on or off, it's either allowing no current through or letting all current through with no resistance, so no heat generated. But it can't go from 0 to infinite resistance instantly, so during the switching it has a resistance value that lets current through, and generates heat. GaN transistors (GaNFETs)do this switching a lot faster, so they generate less heat while switching quickly, thus wasting less power. High-end PSUs however tend to use a circuit called ZVS (Zero-Voltage Switching) with LLC topology. Basically what it means is they have a certain layout of components that resonate with each other, and oscillate the voltage naturally. If you time this correctly with your switching frequency, the power will be off while the transistor is switching. Therefore, you will have almost no power loss due to switching, even though you're using regular transistors. Right now this kind of circuit is either too big, too expensive, not efficient for lower power levels, or a combination of the three to be used for USB chargers, so they use GaNFETs to reduce the switching losses instead. The only place where it might increase efficiency is for the part of the power supply that downconverts the 12V used by most components to 5V and 3.3V. They don't use much power, though, so you will not see huge efficiency increases. Ironically it will probably help most with powering USB devices connected to your PC.
Disclaimer: I'm not an expert so I may have some inaccuracies
Why no GaN ATX PSUs? Because GaN is used in chargers primarily for marketing reasons.
If top ATX PSU manufacturer used GaN then all smaller manufacturers would say GaN on their products too. Especially Chinese companies (they like to compete with specs, numbers, features).
Silicon is plenty fast enough. 4GHz CPU is silicon.
GaN is more expensive so if you’re engineering an ATX PSU, why would you use GaN?
If you’re engineering a charger, you have to use GaN somewhere otherwise consumers won’t buy your product because they think GaN is important.
It is used, search for Corsair AX1600i, it came out in 2018.
The problem it's not cheap,
but it allows high efficiency and compact design.
Thank you 🌍🤖🇱🇷🇮🇳🤠
Why do bridge rectifiers directly connect to high-voltage AC? Why does it not connect with the transformer at first?
The whole point of switching power supplies is that the AC frequency is very low, so you would need a huge transformer to convert it. Instead of doing that, modern power supplies multiply the frequency by first rectifying and smoothing AC to DC and then using a (GaN) mosfet to create a much-much-much higher frequency AC that can be converted by a tiny transformer, as the video explains.
@@tamask001 Thank you a lot for your reply, which is very easy to understand.
Can I always keep a gan charger connected to the wall so it is ready when I want to use it?
Sure.
i still dont understand. So GAN charger are better than traditional charger?
In a nutshell, yes.
@@ChargerLABbecause silicon can’t switch fast enough? I don’t believe it.
Also, why is a bigger bandgap an advantage? Bigger bandgap is higher voltage drop (equals higher losses).
But GaN has a higher Ve band of 3.4V, which is about 1V for silicon
This makes GaN less favorable as a diode
Synchronous rectification with two transistors and no diode is used in high efficiency circuits. The voltage drop of diodes is not that important now. Or high voltage Schottky SiC diodes can be used. I'm not sure if GaN can build Schottky type diodes.
🙂👍
Good explanation of the use of the technology. I forgot the total size is mostly determined by the transformer.
Have you done any videos on switched capacitor converters? I've heard they are what phones use for fast charging now, but I don't understand how they work.
Informative content ❤
Thank you 🙂
Gosh this channel is amazing
Can you make a video of transformer design used in charger
Like it's primary & secondary turn and gauge
How we calculate this
Calculate the in and out voltage, and the in and out current needed. The voltage ratio is the same as the primary to secondary turns ratio.
Please do a charging and breakdown review for Baseus Mini Gan5 20W charger 🙌🏼
Thank you! 🙌🏼
Bom.
great video
But how we calculate gauge of primary and secondary turn
wow I'm first lol
first view, first like, first comment
Thanks man lol 👍
Thanks,informative video about GaN
Glad you liked it
Good ❤