addendum to 45-year MOSFET history, comments?

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 I've written an addendum to the 18-page 45-year
 power MOSFET history article for the x-Chapters.

https://www.dropbox.com/s/0qh8dxgielrkqvq/chap-3x.11_MOSFET-saga_2019-07-19.pdf?dl=1

 And would appreciate your comments.  Here it is:

As we leave this lengthy section, discussing various intricacies  
in the history of power MOSFETs, we have to admit not mentioning  
a few important MOSFET topics:  

(1.) RF power MOSFETs.  These are specialized beasts that work  
to high power levels (750 watts) and to high frequencies (tens  
of GHz).  This is a very active fast-growing area.

(2.) Lateral power MOSFETs.  These avoid using V-grooves and  
other high-channel-density schemes.  They feature a negative  
tempco bias property, see sections 3.6.4 and 3x.18, are  
required meat for high-power linear audio power amplifiers.  
ProFusion sells parts made by Exicon.   Hitachi abandoned the  
market, and now users pray these parts won't disappear.

(3.) Depletion-mode MOSFETs.  Unlike enhancement-mode MOSFETs,  
which are normally off and require a positive bias to turn on,  
these are normally on, and require a reverse-bias to turn off.  
See the discussion in section 3.6.2 and Table 3.6 of the main  
book, and also section 9.3.14 for applications.  In this volume  
see sections 3x.6, 4x.23, 9x.3 and 9x.12.  Very nice depletion-
mode parts are available, and seem to have a stable marketplace,  
however we aren't seeing new parts being introduced.  There are  
only n-channel types available.

(4.) Pioneered by companies like Agilent (spun off to Avago, and  
purchased by Broadcom), super-fast high-frequency small-signal  
MOSFETs flourished.  With technologies like pHEMT (pseudomorphic  
high-electron-mobility transistor) and E-pHEMT (enhancement-mode  
pHEMT), we got inexpensive discrete parts like Avago's ATF-38143,  
a 10GHz 4-volt 200mA FET in a convenient 4-lead SC-70 package.  
But these handy parts have disappeared, as semiconductor  
manufacturers created IC-based solutions more attractive to the  
telecom customer base.**  Now we are left with parts like the  
SAV-551+, made by Mini-Circuits (thank you!) and not even  
appearing on Octopart  This part substitutes for Avago's  
ATF-55143, and features 2 ohms Ron and 0.4pF Cout, numbers we  
were getting used to in the good-old-days.

** footnote: Of the parts on John Larkin's 2017 small pHEMT list  
(with pinouts and SMT labels), only CEL's CE3514 is still  
available, and Mouser has a pile of SKY65050 parts left in stock.


--  
 Thanks,
    - Win

Re: addendum to 45-year MOSFET history, comments?
wrote:

Quoted text here. Click to load it

The really sad demise is the ATF-50189, a power phemt in a SOT-89
package. It was rated for 7 volts but, in the tradition of RF parts,
was good for a lot more. I have/had a beautiful pulse generator output
stage, and some great laser drivers, that use them.

There were nice SOT-89 mesfets, long gone.

I'm having to transition some designs to GaN, which needs a lot more
gate drive, but can switch a lot more volts.

With a roughly factor of 4 improvement in slew and swing, we might
consider opamps.

SAV-551 is a nice little part. Rds-on is impressive.



--  

John Larkin         Highland Technology, Inc

lunatic fringe electronics  


Re: addendum to 45-year MOSFET history, comments?
On 28/07/2019 2:18 pm, Winfield Hill wrote:
Quoted text here. Click to load it

Thanks Win, I have just dipped in so far but on page99, second line  
(about SIC gate drive):

...s (early SiC parts required +20 V and 5 V), b...

Shouldn't that be -5V?

Over-enhancing (a depletion mode part) and over-depleting (an  
enhancement mode part) are worthwhile tricks to keep in the designers  
toolbox. After-all the zero bias distinction between enh and depl is not  
always so simplistic.

piglet



Re: addendum to 45-year MOSFET history, comments?
piglet wrote...
Quoted text here. Click to load it

 Yes, thanks, I've fixed it.


--  
 Thanks,
    - Win

Re: addendum to 45-year MOSFET history, comments?
wrote:

Quoted text here. Click to load it


The gates of silicon mosfets can be driven plenty hard without fear of
blowing out the gate oxide. The margin is roughly 8:1. SiC fets seem
to have very little margin between good gate drive and destruction.

Given the high equivalent gate resistances of many SiC parts, they
need to be driven hard to switch fast.

GaN gates are similarly restricted. Not much more than a healthy drive
voltage can damage them.


--  

John Larkin         Highland Technology, Inc

lunatic fringe electronics  


addendum to 45-year MOSFET history, comments?
I have not had the time to read it through thoroughly, but I do not see the
 Spirito effect mentioned:

https://www.google.com/search?client=safari&channel=iphone_bm&source=
hp&ei=1i8-XdiZKoOKrwSf0q4I&q=spirito+effect&oq=spirito+eff&gs_l=mob
ile-gws-wiz-hp.1.0.0l2j0i22i30l6.9576.15921..16887...0.0..0.164.1147.10j3..
....0....1.......0..46j46i275j0i10.vrrvDa3Mf-g

Cheers  

Klaus

Re: addendum to 45-year MOSFET history, comments?
Klaus Kragelund wrote...
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 It's going to get a proper mention.


--  
 Thanks,
    - Win

Re: addendum to 45-year MOSFET history, comments?
On 28.07.19 2:18 PM, Winfield Hill wrote:
Quoted text here. Click to load it

Small suggestion: Mentioning e-pHEMT right next to the ATF-38143, which  
is a depletion-mode part seems a bit suboptimal. Maybe just leave out  
the e/d distinction altogether?

  ? David

Re: addendum to 45-year MOSFET history, comments?
On 7/29/19 9:13 AM, David Nadlinger wrote:
Quoted text here. Click to load it


RIP.

Cheers

Phil Hobbs

--  
Dr Philip C D Hobbs
Principal Consultant
We've slightly trimmed the long signature. Click to see the full one.
Re: addendum to 45-year MOSFET history, comments?
Phil Hobbs wrote...
Quoted text here. Click to load it

 Yes, I noticed that issue, will re-write a few sentences.


--  
 Thanks,
    - Win

Re: addendum to 45-year MOSFET history, comments?
On 7/28/19 9:18 AM, Winfield Hill wrote:
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<snip>
Quoted text here. Click to load it
Did Skyworks discontinue it?

Cheers

Phil Hobbs

--  
Dr Philip C D Hobbs
Principal Consultant
We've slightly trimmed the long signature. Click to see the full one.
Re: addendum to 45-year MOSFET history, comments?
Phil Hobbs wrote...
Quoted text here. Click to load it

 Hard to say.  The product page doesn't say so, but they only
 list RichardsonRFPD and themselves as sources.  For themselves,
 they say zero inventory.  It doesn't look good.


--  
 Thanks,
    - Win

Re: addendum to 45-year MOSFET history, comments?
On 28.07.19 2:18 PM, Winfield Hill wrote:
Quoted text here. Click to load it

On a related note, does anyone here have 1/f noise measurements for the  
CE3512K2 or CE3514M4?

  ? David

Re: addendum to 45-year MOSFET history, comments?
On 28.07.19 2:18 PM, Winfield Hill wrote:
Quoted text here. Click to load it

Qorvo appear to sell some discretes as well [1], but unfortunately they  
seem to only be available in die form. Probably not worth a mention  
because of that, but it might be an option if one absolutely needed the  
smallest input capacitance possible.

  ? David


[1] https://www.qorvo.com/products/discrete-transistors/gaas-phemts

Re: addendum to 45-year MOSFET history, comments?
On Mon, 29 Jul 2019 15:44:51 +0100, David Nadlinger

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Quoted text here. Click to load it


We went through an extended NDA process with Qorvo before we could see
data sheets for some unremarkable laser drivers. And then the prices
were 4x what we considered reasonable. I suspect they only want to
sell parts by the billion.


--  

John Larkin         Highland Technology, Inc

lunatic fringe electronics  


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