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From: Bill Sloman <bill.sloman@ieee.org>
Newsgroups: sci.electronics.design
Subject: Re: LTSpice model for a SiC MOSFET
Date: Mon, 19 May 2025 12:23:54 +1000
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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.

-- 
Bill Sloman, Sydney