Gan

[Irilia]

I'm trying to find example of Gan adjustable power supply schematic, but I don't find any, (it's possible I don't search the right way) but I need to understand how it works to progress on my power supply.
The simple the circuit is the best it is.
Thanks Irilia.

[Andy Chee]

Do you understand how a normal MOSFET adjustable power supply works?  It will be mostly the same as a GAN adjustable power supply.

[Irilia]

I know that but for what I looked, in physical power supply, the numbers of components is always way lower in gan power supply, so it's why I'm asking

[Andy Chee]

It would be helpful if you posted a link to where you looked before.

[Alex Eisenhut]

power supply semantics

You may have better luck looking for schematics.

[Irilia]

Fail 😅 was obviously what I wanted to say.

[temperance]

This question is very generic. Which type of power supply are you looking for which you think Gan devices will be a better fit?

[Irilia]

AC to DC bench adjustable power supply (so the size and Heat is important) (efficiency) 0 to 100V 0 to 30A this is I think I good goal from the output of the power supply.

[tooki]

That is a very ambitious specification, especially if you mean it to allow 100V at 30A (3000W).


Anyway, you made some claims about regular MOSFET vs GaN circuits before. And we asked you to share those schematics. Please do that.

[temperance]

AC to DC bench adjustable power supply (so the size and Heat is important) (efficiency) 0 to 100V 0 to 30A this is I think I good goal from the output of the power supply.

You are thinking about a phase shifted full bridge?

There are some reference designs available for phase shifted full bridge converters. But most of those employ MOSFET's. Changing the drive circuits to use Gan devices is possible.

Most bench power supplies use two switch forward or two switch fly back converters (maybe interleaved) because non of those ZVS/ZCS converters can handle the wide load range and transient requirements you aim for in a bench power supply of which short circuiting the supply is probably the hardest part to solve. Some well known kW range adjustable switch mode power supplies are current mode two switch forward converters. Nothing beats those when it comes to robustness.

If you search the web you will find various attempts at improving the two switch forward to switch under ZVS conditions. But those often require a floating switch of some kind.

[Irilia]

Very interesting, I have to say the priority is efficiency over size.
The double MOSFET option doesn't seem Bad at all (seems more durable, and more efficient).
For the short circuit problem generally you use a relay to solve this problem (and a control circuit, but I don't think this is directly part of the power supply).
For the efficiency I was curious if I should consider 3 stage
So 3 adjustable input because for what I know if you use a power supply disign for 100V 30A at 5V 1A it will not be really efficient (or it's possible I'm wrong).

Thanks.

[temperance]

For the short circuit problem generally you use a relay to solve this problem (and a control circuit, but I don't think this is directly part of the power supply).

Me thinks Tooki will have to wait forever before any of those GaN claims will be proven if you venture into developing a 100 V 30 A power supply.

Is this going to be a part of: https://www.eevblog.com/forum/oshw/the-station/msg5623197/#msg5623197

If so I think you have a lot to learn. Nothing wrong with that of course. But because of your limited knowledge you underestimate what you are asking. A power supply like this is not something you can copy and paste from an app note and get it working with a little help here and there.

I don't want to discourage you but start by learning the basics by developing for example your own 0...24 V 1 A linear power supply without copying and pasting anything from the internet. By doing so you will find out why a relays isn't going to work to protect your power supply.

[Irilia]

Every power supply have seen use a relay for this Task (I know I still need a very small current to verify if the short is still here.
It's effectively part of the station (I know lots of fun in perspective) but I think it's something really missing on the market, the goal is to be able to offer a prosumer product for the highest grade, but I hope some people can help me, it's extremely difficult to understand everything. Some people are just specialist in the domain. I still have lots of work to get every module working together.
I wasn't expecting to find already done schematic for this application, it's not how it works in electronic (especially when you want the best efficiency)

[Andy Chee]

the numbers of components is always way lower in gan power supply

In my opinion, component count will be roughly the same. 

On the other hand, I can understand that physical size may be smaller with GaN.  But numbers of components will be the same as MOSFET design.

Please provide examples.

[Irilia]

This for example

[Andy Chee]

This for example

To me, that looks like any normal MOSFET design.

Please post an example of MOSFET vs. GaN.

I specifically want to visually inspect numbers of components.

[temperance]

Don't waste your time on and other peoples time. You have no idea about all that and just guessing.

I think you should relax your goals quite a bit. A reasonable bench power supply is about 30 V 1..2 A.

The relays question:
maybe you've seen a relays on the output of an SMPS. But the relays alone will never protect an SMPS from surviving a dead short. As stated before, what you need is current mode control.

[coppice]

the numbers of components is always way lower in gan power supply

In my opinion, component count will be roughly the same. 

On the other hand, I can understand that physical size may be smaller with GaN.  But numbers of components will be the same as MOSFET design.

Please provide examples.

For higher powered designs the high power side might have less parts, as you may not need to spread the work over multiple power transistors when there is less heat to deal with.

[T3sl4co1l]

Don't waste your time on and other peoples time. You have no idea about all that and just guessing.

Well, no need to be rude.

To me, that looks like any normal MOSFET design.

Please post an example of MOSFET vs. GaN.

I specifically want to visually inspect numbers of components.

It's a standard package, nowadays; the 8x8 DFN is used for many parts, including Si, SiC and GaN.

Another fairly clear signal is: why are they using a schottky rectifier?  To justify the cost of GaN on the primary side, surely a sync rect would be used on the secondary.  The transformer would likely be smaller as well (reflecting the higher Fsw).

---

As you can see, there are many indications apparent, even from fairly low-detail photos such as these.  Learn to recognize manufacturer logos, figure out how to look up SMT part codes, find datasheets; look into evaluation designs, see how things are typically done, recognize those same circuits (often lifted verbatim, or give or take minor component values or EMI filtering) in products; and most of all, keep reading and learning about everything around you.  Electronics is a vast subject, take your time; it was years of study before I was proficient in SMPS, and more and more subtleties continue to show themselves.  Over time, your understanding of the world will improve, you'll recognize more and more things at a glance, see why something is done one way or another, etc.

Tim

[inse]

This for example

The photo shows a circuit with integrated controller and power stage (U1), this for sure has less components.
But is this GaN, do integrated solutions in GaN exist?

[ebastler]

AC to DC bench adjustable power supply (so the size and Heat is important) (efficiency) 0 to 100V 0 to 30A this is I think I good goal from the output of the power supply.

Linear regulation, of course, and passively cooled -- right? 

[temperance]

Don't waste your time on and other peoples time. You have no idea about all that and just guessing.

Well, no need to be rude.

You are right. I will edit my post.

[xvr]

Linear regulation, of course, and passively cooled -- right?

Who knows? OP creates combo with this regulator and soldering tools (hot air and soldering gun). May be this is a heater for them? 

[Someone]

AC to DC bench adjustable power supply (so the size and Heat is important) (efficiency) 0 to 100V 0 to 30A this is I think I good goal from the output of the power supply.

Linear regulation, of course, and passively cooled -- right? 

at maximum efficiency!

[Irilia]

Don't waste your time on and other peoples time. You have no idea about all that and just guessing.

Well, no need to be rude.

To me, that looks like any normal MOSFET design.

Please post an example of MOSFET vs. GaN.

I specifically want to visually inspect numbers of components.

It's a standard package, nowadays; the 8x8 DFN is used for many parts, including Si, SiC and GaN.

Another fairly clear signal is: why are they using a schottky rectifier?  To justify the cost of GaN on the primary side, surely a sync rect would be used on the secondary.  The transformer would likely be smaller as well (reflecting the higher Fsw).

---

As you can see, there are many indications apparent, even from fairly low-detail photos such as these.  Learn to recognize manufacturer logos, figure out how to look up SMT part codes, find datasheets; look into evaluation designs, see how things are typically done, recognize those same circuits (often lifted verbatim, or give or take minor component values or EMI filtering) in products; and most of all, keep reading and learning about everything around you.  Electronics is a vast subject, take your time; it was years of study before I was proficient in SMPS, and more and more subtleties continue to show themselves.  Over time, your understanding of the world will improve, you'll recognize more and more things at a glance, see why something is done one way or another, etc.

Tim

Thanks for your message very interesting, I'm always interested by learning new things, what I'm creating is not technically a new product, it's just creating a product Scalable adapted to everyone, simple, but also by reducing the numbers of components, for example you don't need a screen on every separated device, if you have multiple tool in the same box 😉