fast diodes gone...

[John Larkin]

There used to be a bunch of low-barrier schottky diodes with Cjo << 1
pF and equivalent series resistance < 5 ohms, SC79 package.

BAT63
SMS1546
SMS3927

but they seem to be all gone. Strange.

SMS3922 is available, with C=0.7 pF and Rs = 9 typ.

Maybe I can use a small phemt as a diode.

It seems as if quantity-billion ICs keep killing off fast discrete
parts.

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

 

[Phil Hobbs]

John Larkin wrote:

There used to be a bunch of low-barrier schottky diodes with Cjo << 1
pF and equivalent series resistance < 5 ohms, SC79 package.

BAT63
SMS1546
SMS3927

but they seem to be all gone. Strange.

SMS3922 is available, with C=0.7 pF and Rs = 9 typ.

Maybe I can use a small phemt as a diode.

It seems as if quantity-billion ICs keep killing off fast discrete
parts.

You can still get BAT15s.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[John Larkin]

On Fri, 7 Jan 2022 15:03:14 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

John Larkin wrote:
There used to be a bunch of low-barrier schottky diodes with Cjo << 1
pF and equivalent series resistance < 5 ohms, SC79 package.

BAT63
SMS1546
SMS3927

but they seem to be all gone. Strange.

SMS3922 is available, with C=0.7 pF and Rs = 9 typ.

Maybe I can use a small phemt as a diode.

It seems as if quantity-billion ICs keep killing off fast discrete
parts.

You can still get BAT15s.

We\'re stocking SMS7621/BAT15 in the same stock bin now. There looks to
be a big difference in Ron, 18 vs 4.5 ohms. I\'ll have to see what\'s
actually in the bin.

Thanks

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

 

[John Larkin]

On Fri, 07 Jan 2022 12:30:04 -0800, John Larkin
<jlarkin@highland_atwork_technology.com> wrote:

On Fri, 7 Jan 2022 15:03:14 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

John Larkin wrote:
There used to be a bunch of low-barrier schottky diodes with Cjo << 1
pF and equivalent series resistance < 5 ohms, SC79 package.

BAT63
SMS1546
SMS3927

but they seem to be all gone. Strange.

SMS3922 is available, with C=0.7 pF and Rs = 9 typ.

Maybe I can use a small phemt as a diode.

It seems as if quantity-billion ICs keep killing off fast discrete
parts.

You can still get BAT15s.

We\'re stocking SMS7621/BAT15 in the same stock bin now. There looks to
be a big difference in Ron, 18 vs 4.5 ohms. I\'ll have to see what\'s
actually in the bin.

Thanks

But I can\'t find BAT15 in SC-79. I might have to use the awful little
leadless thing.

https://www.mouser.com/ProductDetail/Infineon-Technologies/BAT-15-02LS-E6433?qs=nTClRYuuQBpQitX3%2F947mA%3D%3D

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

 

[Lasse Langwadt Christensen]

fredag den 7. januar 2022 kl. 20.18.27 UTC+1 skrev John Larkin:

There used to be a bunch of low-barrier schottky diodes with Cjo << 1
pF and equivalent series resistance < 5 ohms, SC79 package.

BAT63

+16000 in stock

https://www.arrow.com/en/products/bat6302vh6327xtsa1/infineon-technologies-ag?utm_campaign=octopart_2020&utm_currency=USD&utm_keyword=BAT6302VH6327XTSA1&utm_medium=aggregator&utm_content=inv_listing&region=nac&utm_source=octopart

> SMS1546

several places with 10s of thousands in stock
https://www.digipart.com/part/SMS1546-005LF

 

[Phil Hobbs]

John Larkin wrote:

On Fri, 07 Jan 2022 12:30:04 -0800, John Larkin
jlarkin@highland_atwork_technology.com> wrote:

On Fri, 7 Jan 2022 15:03:14 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

John Larkin wrote:
There used to be a bunch of low-barrier schottky diodes with Cjo << 1
pF and equivalent series resistance < 5 ohms, SC79 package.

BAT63
SMS1546
SMS3927

but they seem to be all gone. Strange.

SMS3922 is available, with C=0.7 pF and Rs = 9 typ.

Maybe I can use a small phemt as a diode.

It seems as if quantity-billion ICs keep killing off fast discrete
parts.

You can still get BAT15s.

We\'re stocking SMS7621/BAT15 in the same stock bin now. There looks to
be a big difference in Ron, 18 vs 4.5 ohms. I\'ll have to see what\'s
actually in the bin.

Thanks

But I can\'t find BAT15 in SC-79. I might have to use the awful little
leadless thing.

https://www.mouser.com/ProductDetail/Infineon-Technologies/BAT-15-02LS-E6433?qs=nTClRYuuQBpQitX3%2F947mA%3D%3D

They claim that a full reel is _seventy thousand_ diodes!

I once did a sampler proto that used two of those in mid-air, hand
soldered. Tended to melt about four solder joints at once.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[John Larkin]

On Fri, 7 Jan 2022 12:40:23 -0800 (PST), Lasse Langwadt Christensen
<langwadt@fonz.dk> wrote:

fredag den 7. januar 2022 kl. 20.18.27 UTC+1 skrev John Larkin:
There used to be a bunch of low-barrier schottky diodes with Cjo << 1
pF and equivalent series resistance < 5 ohms, SC79 package.

BAT63

+16000 in stock

https://www.arrow.com/en/products/bat6302vh6327xtsa1/infineon-technologies-ag?utm_campaign=octopart_2020&utm_currency=USD&utm_keyword=BAT6302VH6327XTSA1&utm_medium=aggregator&utm_content=inv_listing&region=nac&utm_source=octopart

That\'s cool, 0.75 pF and (eyeball estimate) 5 ohms. I\'ll get some.

SMS1546

several places with 10s of thousands in stock
https://www.digipart.com/part/SMS1546-005LF

Looks like brokered old stock. The -005 is a dual in SOT23. Obsolete
too.

Thanks

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

 

[John Larkin]

On Fri, 7 Jan 2022 15:59:57 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

John Larkin wrote:
On Fri, 07 Jan 2022 12:30:04 -0800, John Larkin
jlarkin@highland_atwork_technology.com> wrote:

On Fri, 7 Jan 2022 15:03:14 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

John Larkin wrote:
There used to be a bunch of low-barrier schottky diodes with Cjo << 1
pF and equivalent series resistance < 5 ohms, SC79 package.

BAT63
SMS1546
SMS3927

but they seem to be all gone. Strange.

SMS3922 is available, with C=0.7 pF and Rs = 9 typ.

Maybe I can use a small phemt as a diode.

It seems as if quantity-billion ICs keep killing off fast discrete
parts.

You can still get BAT15s.

We\'re stocking SMS7621/BAT15 in the same stock bin now. There looks to
be a big difference in Ron, 18 vs 4.5 ohms. I\'ll have to see what\'s
actually in the bin.

Thanks

But I can\'t find BAT15 in SC-79. I might have to use the awful little
leadless thing.

https://www.mouser.com/ProductDetail/Infineon-Technologies/BAT-15-02LS-E6433?qs=nTClRYuuQBpQitX3%2F947mA%3D%3D

They claim that a full reel is _seventy thousand_ diodes!

I once did a sampler proto that used two of those in mid-air, hand
soldered. Tended to melt about four solder joints at once.

Cheers

Phil Hobbs

The BAT63 looks good. My bottom line is low C, low L, and minimum
voltage drop at 30 mA, which is about 0.34 volts for the BAT63. The
board is laid out for SC79 already.

I\'m using an SMS7621 now, only about 0.25 pF, but 16 or 18 ohms Rs,
depending on which data sheet to believe.

These tiny parts are a pain to solder. 63/37 solder can be sudden.
Solid or liquid, no gooey phase.

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon