What the heck does Hexfet mean?

Thread Starter

jgreene44

Joined Dec 8, 2016
108
Hello
Thanks in advance.














































Hello,
Thanks in advance for being here. I did try to find the answer online first. however i still do not know
what it means. I am thinking perhaps its a mosfet that can swap polarity. idk.
 

MaxHeadRoom

Joined Jul 18, 2013
19,157
IR coined the phrase of their Power Mosfets, It is due to the structure of the cellular source designation in construction they were called U-groove or U-groove structure of the die.
I can post more from the original manual if needed.
Or better still Google IR AN936a
Max.
 

EM Fields

Joined Jun 8, 2016
583
Hello, thanks in advance for being here. I did try to find the answer online first. however i still do not know what it means. I am thinking perhaps its a mosfet that can swap polarity. idk.
HEXFET Power MOSFET is a trademark of International Rectifier’s Power MOSFETs.
 

WBahn

Joined Mar 31, 2012
24,850
I always think that it is an homage to the magical nature of semiconductors and the hexes they seem to cast on the many people that abuse them (and many people that don't). :D

But, as Max said, it is simply a trademarked name of a particular layout structure in which the cells were hexagonally shaped in order to get greater channel width in the same die area.

https://en.wikipedia.org/wiki/Power_MOSFET#Layout
 

crutschow

Joined Mar 14, 2008
23,487
From Google Images for HEXFET MOSFET:

The HEXFET surface is characterized by a multiplicity of closed hexagonal source cells (over 500,000 per square inch) from which the name HEXFET is derived.

Here's a picture of its construction:
upload_2017-5-13_10-38-43.png

They apparently give better performance in audio amplifiers than vertical MOSFETs.
 

MaxHeadRoom

Joined Jul 18, 2013
19,157
That is also shown in the IR AN936a, I still have the hard copies of Power Hexfet Designer Manuals that IR distributed on launching their Hexfet line.
Max.
 

Thread Starter

jgreene44

Joined Dec 8, 2016
108
Ok this all explains a lot. only thing im still not getting is... what channel are these? p? n? both? All the ones
I have looked at seem to make no mention!
 

MaxHeadRoom

Joined Jul 18, 2013
19,157
You have P & N channel Mosfets.
The difference to a Bi-polar transistor is the Mosfet is a trans-conductance device similar to a tube or valve.
Max.
 

Thread Starter

jgreene44

Joined Dec 8, 2016
108
A few seconds with Google:
Yes I love wasting peoples time and energy vs. just looking on google. I am sorry but all the ones I
Had seen up to this point did not list the channel type.

I do thank you all even ones that leave smart comments!
 

MaxHeadRoom

Joined Jul 18, 2013
19,157
Had seen up to this point did not list the channel type.

I do thank you all even ones that leave smart comments!
Apart from the spec sheet, All you have to look is at the symbol, just as you would a bipolar symbol on the spec sheet to recognize it is NPN or PNP.
Were there smart comments??
Max.
 

WBahn

Joined Mar 31, 2012
24,850
Yes I love wasting peoples time and energy vs. just looking on google. I am sorry but all the ones I
Had seen up to this point did not list the channel type.

I do thank you all even ones that leave smart comments!
Admittedly, I used a very non-intuitive search term. I Googled "hexfet" and looked at the first several listings.
 

Thread Starter

jgreene44

Joined Dec 8, 2016
108
Still does not change the fact that I did not have the same result. Since you are soooo interested in making your point. I had not even
so much as known they exist when i found one in a scrapped item. kept finding them... each time I would look up the part number and it would give the pdf with no channel listed... perhaps I just had a bad run of luck. Perhaps I searched "what is a hexfet" and, not "hexfet"? Maybe I searched "hexfet mosfet" since I had no clue they where the same thing. How bout relax. Your supposed to be helping not trolling.
 

AnalogKid

Joined Aug 1, 2013
8,137
Working from memory ... A while ago, someone figure out that a better way to build a high-power MOSFET is to build a boatload of small MOSFETs in parallel on one die. As with any collection of circular things, there is wasted space between where the circles make contact. IR determined that a mosfet does not have to be a circle, and if you make it a hexagonal shape there is basically zero wasted real estate among the many many small FETs. Hence, the HEXFET.

ak
 

WBahn

Joined Mar 31, 2012
24,850
Still does not change the fact that I did not have the same result. Since you are soooo interested in making your point. I had not even
so much as known they exist when i found one in a scrapped item. kept finding them... each time I would look up the part number and it would give the pdf with no channel listed... perhaps I just had a bad run of luck. Perhaps I searched "what is a hexfet" and, not "hexfet"? Maybe I searched "hexfet mosfet" since I had no clue they where the same thing. How bout relax. Your supposed to be helping not trolling.
I'm not trolling -- I'm trying to point out that you need to learn to do a better job at finding information when you do searches. It's a learned skill (and no one is perfect at it). See if you can find that pdf that you were looking at and post a link. I will take a look and see if I can find information in it that might have been useful in answering your question. If I do, then you will have the opportunity to consider how you might have looked at the material differently and, hence, might look at search results differently in the future.
 
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