Re: The Venerable 741

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Sujet : Re: The Venerable 741
De : jeroen (at) *nospam* nospam.please (Jeroen Belleman)
Groupes : sci.electronics.design
Date : 04. Nov 2024, 11:46:01
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <vga8ee$ta96$1@dont-email.me>
References : 1 2 3 4
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On 11/4/24 00:54, john larkin wrote:
On Sun, 3 Nov 2024 23:17:55 +0100, Jeroen Belleman
<jeroen@nospam.please> wrote:
 
On 11/3/24 23:10, Jeroen Belleman wrote:
On 11/3/24 19:07, Cursitor Doom wrote:
It's been around an awfully long time and there are far better
alternatives out there. But is there still a case for using them in
certain niche applications in 2024?
>
I've used them in power supply regulators exposed to radiation.
Being old designs and all-NPN, they're pretty rad-hard.
>
Jeroen Belleman
>
Blimey, I just checked: It isn't all-NPN! Fortunately
for me, it still kept working under irradiation...
>
Jeroen Belleman
 The early integrated PNPs had betas in the single digits, so a bit of
radiation poisoning was no big deal.
 
Non, au contraire, in bipolar transistors, irradiation tends to
reduce beta at low current. If it's already low to begin with,
a bit of irradiation will soon make it drop to useless values,
and the chip stops working.
My typical example used to be the LM317 as compared to the LM337.
The latter has (had?) a large lateral PNP which did not survive
for long (<50Gy). The LM317 just kept going (>1kGy).
However, chip design changes that do not affect operation under
normal circumstances can radically change radiation resistance.
Jeroen Belleman

Date Sujet#  Auteur
3 Nov 24 * The Venerable 74124Cursitor Doom
3 Nov 24 +* Re: The Venerable 7415john larkin
3 Nov 24 i+* Re: The Venerable 7413Phil Hobbs
3 Nov 24 ii`* Re: The Venerable 7412john larkin
3 Nov 24 ii `- Re: The Venerable 7411Phil Hobbs
3 Nov 24 i`- Re: The Venerable 7411bitrex
3 Nov 24 +- Re: The Venerable 7411Edward Rawde
3 Nov 24 +* Re: The Venerable 7418Jeroen Belleman
3 Nov 24 i`* Re: The Venerable 7417Jeroen Belleman
4 Nov 24 i +* Re: The Venerable 7412john larkin
4 Nov 24 i i`- Re: The Venerable 7411Jeroen Belleman
4 Nov 24 i `* Re: The Venerable 7414bitrex
4 Nov 24 i  `* Re: The Venerable 7413john larkin
4 Nov 24 i   `* Re: The Venerable 7412bitrex
4 Nov 24 i    `- Re: The Venerable 7411john larkin
4 Nov 24 +* Re: The Venerable 7418Jan Panteltje
4 Nov 24 i`* Re: The Venerable 7417Liz Tuddenham
4 Nov 24 i +- Re: The Venerable 7411Jan Panteltje
4 Nov 24 i `* Re: The Venerable 7415john larkin
5 Nov 24 i  `* Re: The Venerable 7414Cursitor Doom
6 Nov 24 i   `* Re: The Venerable 7413Bill Sloman
7 Nov 24 i    `* Re: The Venerable 7412Michael Schwingen
8 Nov 24 i     `- Re: The Venerable 7411Bill Sloman
5 Nov 24 `- Re: The Venerable 7411piglet

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