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Re: A SOT-89 with emitter in the middle

From	John Larkin <jjlarkin@highlandtechnology.com>
Newsgroups	sci.electronics.design
Subject	Re: A SOT-89 with emitter in the middle
Date	2017-12-26 08:43 -0800
Organization	highland technology
Message-ID	<riu44d1ji2pfffkhei8nru06iuuds4lepc@4ax.com> (permalink)
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On 26 Dec 2017 05:34:03 -0800, Winfield Hill
<hill@rowland.harvard.edu> wrote:

>John Larkin wrote...
>>
>> Unfortunately, SOT89 RF transistors get discontinued
>> a lot faster than they get introduced. I designed a
>> wonderful circuit recently, that uses BFQ149s (PNP)
>> parts, and then they were discontinued. Bummer. We
>> bought 11,000 to tide us over for a while, but I'm
>> going to have to redesign eventually.
>
> OK, I'll bite.  What's the wonderful design that'll
> swallow up 11,000 BFQ149s, and come back for more?

It's the output stage of a pulse generator.

One of my nearly lifelong hobbies is designing pulse gen output
stages. Logic level in, 50 ohm out, programmable Vhi and Vlo, fast,
clean, tough, low power dissipation. When I filnally had a really good
one, the BFQ149 went EOL. 

It annoyed me enough that I bought $5000 worth of PNPs so I don't need
to redesign it soon.

-- 

John Larkin   Highland Technology, Inc   trk

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

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Thread

A SOT-89 with emitter in the middle LM <sala.nimi@mail.com> - 2017-12-21 22:07 +0200
  Re: A SOT-89 with emitter in the middle Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> - 2017-12-21 21:55 +0100
    Re: A SOT-89 with emitter in the middle LM <sala.nimi@mail.com> - 2017-12-21 23:51 +0200
      Re: A SOT-89 with emitter in the middle John Larkin <jjlarkin@highlandtechnology.com> - 2017-12-24 10:47 -0800
        Re: A SOT-89 with emitter in the middle Robert Baer <robertbaer@localnet.com> - 2017-12-24 18:27 -0800
          Re: A SOT-89 with emitter in the middle John Larkin <jjlarkin@highlandtechnology.com> - 2017-12-25 08:41 -0800
    Re: A SOT-89 with emitter in the middle Winfield Hill <hill@rowland.harvard.edu> - 2017-12-21 13:54 -0800
      Re: A SOT-89 with emitter in the middle LM <sala.nimi@mail.com> - 2017-12-23 21:27 +0200
      Re: A SOT-89 with emitter in the middle Robert Baer <robertbaer@localnet.com> - 2017-12-23 22:05 -0800
  Re: A SOT-89 with emitter in the middle John Larkin <jjlarkin@highlandtechnology.com> - 2017-12-21 19:51 -0800
    Re: A SOT-89 with emitter in the middle Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> - 2017-12-22 10:34 +0100
      Re: A SOT-89 with emitter in the middle John Larkin <jjlarkin@highlandtechnology.com> - 2017-12-22 08:56 -0800
        Re: A SOT-89 with emitter in the middle Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-12-23 08:01 -0500
        Re: A SOT-89 with emitter in the middle Winfield Hill <hill@rowland.harvard.edu> - 2017-12-26 05:34 -0800
          Re: A SOT-89 with emitter in the middle John Larkin <jjlarkin@highlandtechnology.com> - 2017-12-26 08:43 -0800
            Re: A SOT-89 with emitter in the middle Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-12-26 13:03 -0500
              Re: A SOT-89 with emitter in the middle John Larkin <jjlarkin@highlandtechnology.com> - 2017-12-26 10:36 -0800
            Re: A SOT-89 with emitter in the middle Winfield Hill <hill@rowland.harvard.edu> - 2017-12-27 05:50 -0800
              Re: A SOT-89 with emitter in the middle krw@notreal.com - 2017-12-27 09:34 -0500
              Re: A SOT-89 with emitter in the middle "John Miles, KE5FX" <jmiles@gmail.com> - 2017-12-27 13:42 -0800
                Re: A SOT-89 with emitter in the middle krw@notreal.com - 2017-12-27 19:58 -0500
                Re: A SOT-89 with emitter in the middle John Larkin <jjlarkin@highlandtechnology.com> - 2017-12-27 19:11 -0800
                Re: A SOT-89 with emitter in the middle krw@notreal.com - 2017-12-27 22:44 -0500
                Re: A SOT-89 with emitter in the middle John Larkin <jjlarkin@highlandtechnology.com> - 2017-12-27 20:08 -0800
                Re: A SOT-89 with emitter in the middle krw@notreal.com - 2017-12-27 23:29 -0500
                Re: A SOT-89 with emitter in the middle whit3rd <whit3rd@gmail.com> - 2017-12-28 03:34 -0800
                Re: A SOT-89 with emitter in the middle krw@notreal.com - 2017-12-28 08:42 -0500
                Re: A SOT-89 with emitter in the middle John Larkin <jjlarkin@highlandtechnology.com> - 2017-12-28 08:16 -0800
                Re: A SOT-89 with emitter in the middle boB <boB@K7IQ.com> - 2017-12-28 10:11 -0800
                Re: A SOT-89 with emitter in the middle krw@notreal.com - 2017-12-28 20:03 -0500
                Re: A SOT-89 with emitter in the middle Winfield Hill <hill@rowland.harvard.edu> - 2017-12-28 17:08 -0800
                Re: A SOT-89 with emitter in the middle krw@notreal.com - 2017-12-28 20:28 -0500
  Re: A SOT-89 with emitter in the middle mpm <mpmillard@aol.com> - 2017-12-23 17:12 -0800

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