Giga Mosfet

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Magura

Magura

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Joined 2003
class-a-labs.com
Zen Mod said:



did you tried good one ?

( I presume that peeked one wasn't good for trying ...... :rofl: )
Click to expand...


No, as I saw no point in doing so, due to the rather hefty input capacitance.

It was actually a perfectly good mosfet I opened, as I wondered if it was one big mosfet, or many smaller dies in parallel.

If you take a look at the data sheet, you will find that the input capacitance VS. wattage, is not too far off being the same as a bunch of IRFP xxxx in parallel.

Now, go take a look at "home".

Magura :)
 
F

Fanuc

Member
Joined 2006
Tyimo said:


Yes, please!:)

Tyimo
Click to expand...

Check out advanced power technologies power mosfet modules. 750w in a SOT 224/227 (recalling from memory) package (more for bus bar use). They are almost certainly what the devices are.

I was referring to much bigger mosfets like 50A-200A continous types for motor use.

PS. Can't seem to find this company anymore! Has it been taken over recently? Or was it Applied power technologies ? US company.

Kevin
 
Nelson Pass

Nelson Pass

The one and only
Joined 2001
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Of course it is clear that the devices are not being run any where
near their ratings. If you want to play with this circuit, there is no
need to chase down those particular parts, and it is clear that they
are parallel devices in a package anyway.

Interestingly, because they have been designed for switching, you
do not have an assurance that those chips are actually matched
for linear operation.

:cool:
 
F

Fanuc

Member
Joined 2006
Lars Clausen said:
I'd suggest going for a single die device instead of a random SOT227 part.

The biggest one you can get will disappate upwards of 800W from a single die, and then you don't have the potential oscillation problem associated with using the random twin die part, in the linear region.
Click to expand...

Originally posted by Nelson Pass
Interestingly, because they have been designed for switching, you
do not have an assurance that those chips are actually matched
for linear operation.
Click to expand...

This is wrong, being made on the same case/fabrication means the capacitances/characterisitics align very closely otherwise you will get hotspots etc and it wouldn't be a 750 watt part with manufacturer's warranty or SOA! .

Regards

Kevin
 
Nelson Pass

Nelson Pass

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Joined 2001
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Fanuc said:
This is wrong, being made on the same case/fabrication means the capacitances/characterisitics align very closely otherwise you will get hotspots etc and it wouldn't be a 750 watt part with manufacturer's warranty or SOA! .
Click to expand...

I don't doubt that the chips are from the same lot code, but that is no
assurance that the Vgs is matched. If the part is designed for switching,
the manufacturer is unlikely to care about that and is unlikely to go to the
trouble of matching dies. If they did, I expect that the data sheets would
be bragging about it.

:cool:
 
T

Tyimo

Member
Joined 2002
Lars!

I'd suggest going for a single die device instead of a random SOT227 part.

The biggest one you can get will disappate upwards of 800W from a single die, and then you don't have the potential oscillation problem associated with using the random twin die part, in the linear region.
Click to expand...
Please show me one! Which model?

Greets:

Tyimo
 
MEGA_amp

MEGA_amp

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h_a

h_a

Member
Joined 2006
That Coolmos is in a stock TO-247 package, so you can load it at best with about 30 W - just as the original parts.

Well, but the 40 S transconductance could help :D

A real switcher, not even a transconductance plot in the datasheet.

Have fun, Hannes
 
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