Well, it happened--the last fast PNP is EOL

They sell for a lot more than digital transistors or BCX71s, and can't be much harder to make. Nexperia didn't take NXP's rf transistors or JFETs, so they're getting rid of them.

Cheers

Phil Hobbs

Given the choice, TI is our preferred vendor, because they tend to keep stuff in production. Conversely, we avoid NXP.

I emailed ON and suggested they do some fast PNPs. They replied that demand is too small.

TI has some nice class-D amps.

Depends. Decades ago some engineers used the expression "Texan call-off" and I got involved in an urgent redesign because some kind of logamp had suddenly been discontinued.

I'll have to look at them again, ours was from Infineon. Problem is, we need 200V abs max for swing.

A company that made it onto my blacklist recently is Broadcom after they obsoleted a whole slew of discretes.

The EOL of discretes does keep fast circuit design interesting. GaN parts are cheap and fast, but don't come in P-channel!

John Larkin wrote: ..

I wondered that the military sector kept calm about the obsolation...

-- Uwe Bonnes snipped-for-privacy@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt

--------- Tel. 06151 1623569 ------- Fax. 06151 1623305 ---------

Maybe we could get THAT or somebody to do them.

Cheers

Phil Hobbs

Yeah, it's like doing chip design circa 1975--the NPNs are 100 times faster than the PNPs. :(

Cheers

Phil Hobbs

There aren't that many... just 18 standard products between 1962 and

At 1970 I fled the corporate political world (I couldn't deal with all the political BS at Motorola... I think I quit 4-times just to force proper engineering decisions) and went to doing virtually all custom... with a few exceptions, like the LVDS chips for Fairchild.

(I supported my family at the time... 1970-1977, by running a hybrid line at Dickson Electronics and writing a lot of the course material for ICE... Integrated Circuit Engineering.)

At last count there were ~200 custom chips. I'll have to ponder and see if I can devise a non-disclosure way of listing those devices... and what they do functionally... if I can I'll post and announce.

In the last five years or so I've tired of chip design... there really isn't anything analog I haven't done before >:-}... so I've hopped into Behavioral Modeling... easy for me since I've done so much circuit work (and my math capabilities, at least up thru Calculus, are superb)... and it's fun, devising functional models which don't divulge any internal IP... a lot like puzzle solving in reverse ;-)

I will be updating the "Jim's Secret Sauce" page shortly, renaming it "Behavioral Modeling Gimmicks/Tools/Not sure yet"... with more explanations of how I got there. Watch for it. ...Jim Thompson

Most of my chip designs, transferred to Lansdale, are on the military preferred components list... they seem to love unconditionally stable OpAmps, even if the open-loop gain is only 75dB... though I'm sure the sliding-class-A outputs and 10V/us slew-rates grab their attention as well ;-) ...Jim Thompson

-- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | STV, Queen Creek, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

Thinking outside the box... producing elegant solutions, by understanding what nature is hiding.

"It is not in doing what you like, but in liking what you do that is the secret of happiness." -James Barrie

"THAT" is a possibility ;-) I did a number of audio things for them, MANY moons ago... using those Intersil (?) wire-up-only chips. ...Jim Thompson

Any radhard opamps in there with CM input range to the negative rail and output to neg rail with pull-down? Will need that soon.

That's stretching history just a tweak... PNP's back then were _laterals_ ... 1MHz GBW product, if you were lucky. ...Jim Thompson

-- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | STV, Queen Creek, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

Thinking outside the box... producing elegant solutions, by understanding what nature is hiding.

"It is not in doing what you like, but in liking what you do that is the secret of happiness." -James Barrie

Not from my just-out-of-school era.

Today, I can easily design that for you... processing by X-Fab. ...Jim Thompson

I'll find some off-the-shelf from "the usual suspects", was just wondering if there was a genuine Thompson amp around in rad-hard.

Sometimes the just out of school designs are like VW Beetles. I have one that runs off the conveyor belt since the 90's, now in Shenzhen, no end in sight.

We did use lots of OP484 :-)

Cheers, Gerhard

The PNP CK722 was the fastest transistor when I was a kid.

NXP: Not recommended for new designs.

Gerhard

Am 05.06.2018 um 21:05 schrieb Phil Hobbs:

Or Diodes, Inc.

Though I am sure the taxpayer was ultimately on the hook for those :-)