Path: ...!eternal-september.org!feeder2.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>
Newsgroups: sci.electronics.design
Subject: Re: Curve Tracers
Date: Wed, 20 Nov 2024 22:21:12 -0000 (UTC)
Organization: A noiseless patient Spider
Lines: 71
Message-ID: <vhlncn$9so0$1@dont-email.me>
References: <vhkhcg$2ip8$2@dont-email.me>
 <o50sjjpmjmrdbvs9po8inhcdn961a0923g@4ax.com>
 <k78sjjpc3c41aae7ts86nomls9a94f4lbg@4ax.com>
 <vhlapb$7msh$1@dont-email.me>
 <bmgsjjpfuumme5e24gfeelu3u5dic93ufg@4ax.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Injection-Date: Wed, 20 Nov 2024 23:21:12 +0100 (CET)
Injection-Info: dont-email.me; posting-host="1f79c4f5d5ebf1b78228a216717f9022";
	logging-data="324352"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX18ShaDAKQq5PCGD5VAiHHZt"
User-Agent: NewsTap/5.5 (iPhone/iPod Touch)
Cancel-Lock: sha1:esr6zZDBUUY67L/RE+KD2RGA03w=
	sha1:5haYMFofJZ/pmcEegfmqlTDEEUk=
Bytes: 3854

Joe Gwinn <joegwinn@comcast.net> wrote:
> On Wed, 20 Nov 2024 18:46:03 -0000 (UTC), Phil Hobbs
> <pcdhSpamMeSenseless@electrooptical.net> wrote:
> 
>> Joe Gwinn <joegwinn@comcast.net> wrote:
>>> On Wed, 20 Nov 2024 07:40:08 -0800, john larkin <JL@gct.com> wrote:
>>> 
>>>> On Wed, 20 Nov 2024 11:32:32 -0000 (UTC), Cursitor Doom
>>>> <cd999666@notformail.com> wrote:
>>>> 
>>>>> Gentlemen,
>>>>> 
>>>>> Curve tracers reveal useful info about the dynamic characteristics of 
>>>>> semiconductors and make designing for same much more predictable and 
>>>>> dependable than relying on spice models and simulation alone. But they're 
>>>>> typically rare beasts and expensive to come by and boat anchor varieties 
>>>>> are seriously heavy and bulky.
>>>>> I think therefore that a curve tracer would make an excellent project, 
>>>>> using the X&Y inputs of a scope as the display. Has anyone here attempted 
>>>>> this? I'd be interested to know what the main challenges are likely to be.
>>>>> 
>>>>> -CD
>>>> 
>>>> I've considered it. It would be much more valuable if it traced
>>>> capacitances too.
>>>> 
>>>> The display should be on a computer and the data archived.
>>>> 
>>>> I often just set up a breadboard and test parts. Last week I blew out
>>>> some power mosfet gates. Some have internal zeners; this one doesn't.
>>>> 
>>>> Most mosfets drain avalanche, but the voltage is never specified, in
>>>> fact deliberately hidden. I have to measure that.  A good curve tracer
>>>> should measure that too.
>>>> 
>>>> Currents should go down to picoamps.
>>>> 
>>>> The fact that there aren't many curve tracers for sale suggests a
>>>> small market.
>>> 
>>> I think that the function is now done by a Fluke Data Bucket (or
>>> equivalent) in an ATE (Automatic Test Equipment) that controls
>>> collection of data, which is later plotted in a computer.
>>> 
>>> Joe Gwinn
>>> 
>> 
>> Nah, real men use an HP 4145B.  Exceptionally Good Medicine. 
> 
> Heh.  Boat anchor for sure.  But it had real knobs, and no Windows.
> 
> And isn't it a bit limited - only tests old semiconductors ...
> 
> Joe
> 

The only two limitations I’ve ever run into are that it boots from a now-
unobtainable nonstandard machine floppy drive and that it only speaks gpib.
(You can get usb replacements.)

Otherwise, it has four high performance SMUs that work well from
miillivolts to 50V and from tens of femtoamps to a couple of hundred
milliamps, easy keyboard configuration, and much more. 

Cheers 

Phil Hobbs 

-- 
Dr Philip C D Hobbs  Principal Consultant  ElectroOptical Innovations LLC /
Hobbs ElectroOptics  Optics, Electro-optics, Photonics, Analog Electronics