no fast PNPs!

Guest
MMBTH81 is almost the last pretty fast, small PNP still standing.


I need to clamp the swing of a fast positive logic level, so

collector to ground
base to +3
emitter to logic level



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
 
On Monday, February 3, 2020 at 12:21:06 PM UTC-5, jla...@highlandsniptechnology.com wrote:
MMBTH81 is almost the last pretty fast, small PNP still standing.


I need to clamp the swing of a fast positive logic level, so

collector to ground
base to +3
emitter to logic level



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

I've been using USB ESD protectors for those sorts of things.
They're claimed to be amazingly fast with fractional pF loading.
But yes, I'd love some GHz PNP's, too.

Cheers,
James Arthur
 
Winfield Hill <winfieldhill@yahoo.com> wrote in
news:r19ndk03vs@drn.newsguy.com:

jlarkin@highlandsniptechnology.com wrote...

Low-capacitance Schottky diode.

PIN diode?
 
Am 03.02.20 um 19:32 schrieb DemonicTubes:
On Monday, February 3, 2020 at 10:21:06 AM UTC-7, jla...@highlandsniptechnology.com wrote:
MMBTH81 is almost the last pretty fast, small PNP still standing.


I need to clamp the swing of a fast positive logic level, so

collector to ground
base to +3
emitter to logic level



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

BF970 are still around....but yeah, since the 90s it looks like options have been dwindling. I'm not exactly sure why.

Unknown @ DK, obsolete @ Mouser, 0 stock.

AFAIK the only fastish PNPs left are these Siliconix/Renesas transistor
arrays.

I still have a reel of BFG31, but cannot design them in for customers.

regards, Gerhard.
 
On Mon, 3 Feb 2020 19:58:12 +0000, piglet <erichpwagner@hotmail.com>
wrote:

On 03/02/2020 5:20 pm, jlarkin@highlandsniptechnology.com wrote:

MMBTH81 is almost the last pretty fast, small PNP still standing.


I need to clamp the swing of a fast positive logic level, so

collector to ground
base to +3
emitter to logic level





50A02CH is only slightly slower?

piglet

That one is a nice combination of speed, voltage, current, and
capacitance. I want minimum capacitance, so can probably still use
MMBTH81, but that is marginal on current. Worst case, I may want to
sink 100 mA for a short time.

I guess I could use a schottky diode into a sinking supply, but the
PNP clamp conveniently dumps the current into ground.

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
 
On 03/02/2020 5:20 pm, jlarkin@highlandsniptechnology.com wrote:
MMBTH81 is almost the last pretty fast, small PNP still standing.


I need to clamp the swing of a fast positive logic level, so

collector to ground
base to +3
emitter to logic level

50A02CH is only slightly slower?

piglet
 
On 2020-02-03 13:51, Gerhard Hoffmann wrote:
Am 03.02.20 um 19:32 schrieb DemonicTubes:
On Monday, February 3, 2020 at 10:21:06 AM UTC-7,
jla...@highlandsniptechnology.com wrote:
MMBTH81 is almost the last pretty fast, small PNP still standing.


I need to clamp the swing of a fast positive logic level, so

collector to ground
base to +3
emitter to logic level



--

John Larkin         Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over
Reason"

BF970 are still around....but yeah, since the 90s it looks like
options have been dwindling.  I'm not exactly sure why.


Unknown @ DK, obsolete @ Mouser, 0 stock.

AFAIK the only fastish PNPs left are these Siliconix/Renesas transistor
arrays.

I still have a reel of BFG31, but cannot design them in for customers.

regards, Gerhard.

Me too, plus two reels of BFT92s. Internal use only.

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
 

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