This is some FET !!!

[EUVL]

Someone posted this at Class D forum :

Power GaN FETS now at DigiKey...

http://epc-co.com/epc/documents/data...heet_final.pdf

Digi-Key - 917-1005-6-ND (Manufacturer - EPC1011)

Very low capacitance, very high transconductance (almost 10S at even below 2A) !!!

Small problem with the bare die, but can be solved.
Larger problem potentially with the high gate current.

Have you already tried them, Nelson ?

Anyone interested in a GB ?


Patrick

[Nelson Pass]

I have not tried them. They look like nice switches, but what
do you suppose the dissipation capability will be?

[EUVL]

That depends on how you package them.
You get an LGA bare die. The rest is in your own hands.
Properly packaged, I expect them to do 100W. The die itself is not small at 3.5x1.4mm.

Actually I should not say FETs. They should be called GaN power transistors.
Looks very linear above 5A, and negative tempco as a bonus.


Patrick

[Andrew Eckhardt]

Well they are glass everywhere except for the solder pads, so unless you have some nifty processing equipment on hand you'd be faced with aligning a direct metal interface to the part. Probably copper, polished, and cold.

[EUVL]

You missed the point.

The die is grown on Si wafer, and the bump pads have no solder balls.
No one forces you to use flip chip.
You can even mount it to a TO247 or whatever else.


Patrick

[Andrew Eckhardt]

Well, no. I can't mount it to a TO247. Maybe someone with some more equipment could. Maybe a group buy could be arranged for 100,000 pieces. I'm not super familiar with these processes, but I think usually lead wires are bonded to the top of the die and the bottom is etched and plated or something so that it may be soldered to a thermal pad. Anything lower performance than that would probably be a waste of time.

[StevenOH]

<<Actually I should not say FETs. They should be called GaN power transistors.>>
They are FETs, Enchancement mode MOSFETs to be precise.

Max. power dissipation can be calculated very easy.
If max. continious drain current specified as 12A, and the max. Ron
is 0.025 Ω (we need the worst case here), then the max. power dissipated
for this case will be Pmax=Id²Ron =3.6W.

The chip actually can withstand currents up to 40A (the pulse
requirement for this is only because of the small case employed).
Coupled with the capacitances figures and the transconductance rough estimate of ~16S@2.5A, practically zero (or negative) current tempco at our
currents of interest, that makes these little creatures really remarkable devices.
Clearly, this is just the first steps of GaN technology.

[Nelson Pass]

It would be nice if they could package them up.

I understand that you can get something packaged in a TO247
with as few as a thousand. It's probably the set up charge
that bites.

[Bigun]

The data sheet says high electron mobility, but GaN on it's own isn't too good if I remember. I suspect this isn't a regular MOSFET where electrons are created under a gate oxide but this a HEMT - a device that forms a 2-dimensional electron 'gas' at the interface between two different layers (probably GaN and AlGaN) where it can exhibit high mobility. HEMTs have been made in the past for microwave use where they exhibit extraordinary speed.

[40 watt]

GaN, to me, has always been a little weird...I much prefer Fibonaccis and a few other things.

...oops! Wrong forum...