Re: LTSpice model for a SiC MOSFET

On 22/05/2025 1:43 am, Edward Rawde wrote:

"john larkin" <jl@glen--canyon.com> wrote in message news:8osr2klq9oepgqsva13nljp4aikmh75rkv@4ax.com...

On Wed, 21 May 2025 09:42:11 -0400, "Edward Rawde"
<invalid@invalid.invalid> wrote:
>

"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:100jsf2$2n1hq$2@dont-email.me...

On 21/05/2025 3:44 am, Edward Rawde wrote:

"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:100ibpi$2at8a$2@dont-email.me...

On 20/05/2025 11:38 pm, Edward Rawde wrote:

"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:100hb9s$24itl$3@dont-email.me...

On 20/05/2025 4:26 am, Edward Rawde wrote:

"Bill Sloman" <bill.sloman@ieee.org> wrote in message news:100epio$1h4ca$1@dont-email.me...

On 19/05/2025 1:38 pm, john larkin wrote:

On Mon, 19 May 2025 12:23:54 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
>

On 19/05/2025 12:15 am, john larkin wrote:

On Sun, 18 May 2025 18:11:58 +1000, Bill Sloman <bill.sloman@ieee.org>
wrote:
>

I'm looking at a problem where somebody wants to step down a 1kV low
current source to 3.3V.
>
The Baxandall class-D oscillator could do it, but it needs a pair 1.7kV
MOSFETs for the job. The Infineon SiC IMH170R450M1 would do it - though
it's a much higher current part (10A) than the job needs (about 1mA).
>
I've dived into the Infineon rabbit-hole which promises LTSpice models,
but wasn't able to find one.
>
Does anybody know of a similar - ideally cheaper and smaller - part for
which there is an LTSpice model?

>
I use a Cree/Wolfspeed 1200v part, C2M0280120D, in my Pockels Cell
driver.
>
https://www.dropbox.com/scl/fi/5arhyamrp0bl3tgb2fasn/DSC02771.JPG?rlkey=3ttcc2yt6s9nrtdouuv3aneol&raw=1
>
They do have an LT Spice model library that works.
>
Gate drive for SiC parts is a bear. I did it myself, but I think there
are chips for that now.
>
There are multi-kilovolt silicon mosfets too.
>
Baxandal looks to be inefficient and expensive as a low power
converter. The drain swing is 2x the supply voltage, and it needs two
fets and a difficult custom transformer.

>
It isn't going to be inefficient. That configuration is famous efficient.
>
The drain swing is actually 1.67 times the supply voltage, but it does
need two switching devices and a specially wound transformer (and we
know how reluctant you are to design them or get them made).
>
It is probably going to be too expensive for the application, and we'd
be grateful for your insights into a cheaper alternative. I can't think
of one.

>
I'm not sure what the specs are, but I have a few ideas.
>
One could make a flyback converter with a high-ratio transformer.
Coilcraft makes some, capacitor charging transformers and CCFLs. There
must be crazy cheap Indian or Chinese CCFL transformers.
>
ST makes a 1400v NPN transistor for under a dollar.

>
But you can't be bothered to post the part number.

>
What you should have said is that you couldn't be bothered to use a search engine.

>
I need at least 1.7kV. A 1400V part isn't interesting.

>
Centuries ago they'd put two transistors in series in the TV horizontal deflection department because a single one didn't
have
enough Vce max.

>
The transistor was invented in the 1950's. Decades ago is closer to the mark.

>
LOL sane people would have known what I meant without needing to point that out Bill.

>
Sane people don't say "centuries" when they mean "decades".

>
Does the word "hyperbole" mean anything to you Bill?

>
He's obviously unwell.

 Yes I think you're right so I'm going to leave it there.

I think I'll rely on my doctor. She's got a medical degree, and does seem to know what she is talking about.
--
Bill Sloman, Sydney