Reply by John Larkin July 29, 20192019-07-29
On Mon, 29 Jul 2019 15:44:51 +0100, David Nadlinger
<david@klickverbot.at> wrote:

>On 28.07.19 2:18 PM, Winfield Hill wrote: >> Now we are left with parts like the >> SAV-551+, made by Mini-Circuits (thank you!) and not even >> appearing on Octopart This part substitutes for Avago's >> ATF-55143, and features 2 ohms Ron and 0.4pF Cout, numbers we >> were getting used to in the good-old-days. >> >> ** footnote: Of the parts on John Larkin's 2017 small pHEMT list >> (with pinouts and SMT labels), only CEL's CE3514 is still >> available, and Mouser has a pile of SKY65050 parts left in stock. > >Qorvo appear to sell some discretes as well [1], but unfortunately they >seem to only be available in die form. Probably not worth a mention >because of that, but it might be an option if one absolutely needed the >smallest input capacitance possible. > > &mdash; David > > >[1] https://www.qorvo.com/products/discrete-transistors/gaas-phemts
We went through an extended NDA process with Qorvo before we could see data sheets for some unremarkable laser drivers. And then the prices were 4x what we considered reasonable. I suspect they only want to sell parts by the billion. -- John Larkin Highland Technology, Inc lunatic fringe electronics
Reply by David Nadlinger July 29, 20192019-07-29
On 28.07.19 2:18 PM, Winfield Hill wrote:
> Now we are left with parts like the > SAV-551+, made by Mini-Circuits (thank you!) and not even > appearing on Octopart This part substitutes for Avago's > ATF-55143, and features 2 ohms Ron and 0.4pF Cout, numbers we > were getting used to in the good-old-days. > > ** footnote: Of the parts on John Larkin's 2017 small pHEMT list > (with pinouts and SMT labels), only CEL's CE3514 is still > available, and Mouser has a pile of SKY65050 parts left in stock.
Qorvo appear to sell some discretes as well [1], but unfortunately they seem to only be available in die form. Probably not worth a mention because of that, but it might be an option if one absolutely needed the smallest input capacitance possible. &acirc;&euro;&rdquo; David [1] https://www.qorvo.com/products/discrete-transistors/gaas-phemts
Reply by David Nadlinger July 29, 20192019-07-29
On 28.07.19 2:18 PM, Winfield Hill wrote:
> [&acirc;&euro;&brvbar;] CEL's CE3514 is still available
On a related note, does anyone here have 1/f noise measurements for the CE3512K2 or CE3514M4? &acirc;&euro;&rdquo; David
Reply by Winfield Hill July 29, 20192019-07-29
Phil Hobbs wrote...
> >On 7/28/19 9:18 AM, Winfield Hill wrote: >> I've written an addendum to the 18-page 45-year >> power MOSFET history article for the x-Chapters. ><snip> >> ** footnote: Of the parts on John Larkin's 2017 small pHEMT list >> (with pinouts and SMT labels), only CEL's CE3514 is still >> available, and Mouser has a pile of SKY65050 parts left in stock. > > Did Skyworks discontinue it?
Hard to say. The product page doesn't say so, but they only list RichardsonRFPD and themselves as sources. For themselves, they say zero inventory. It doesn't look good. -- Thanks, - Win
Reply by Phil Hobbs July 29, 20192019-07-29
On 7/28/19 9:18 AM, Winfield Hill wrote:
> I've written an addendum to the 18-page 45-year > power MOSFET history article for the x-Chapters.
<snip>
> ** footnote: Of the parts on John Larkin's 2017 small pHEMT list > (with pinouts and SMT labels), only CEL's CE3514 is still > available, and Mouser has a pile of SKY65050 parts left in stock. > >
Did Skyworks discontinue it? 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
Reply by Winfield Hill July 29, 20192019-07-29
Phil Hobbs wrote...
> > On 7/29/19 9:13 AM, David Nadlinger wrote: >> On 28.07.19 2:18 PM, Winfield Hill wrote: >>> With technologies like pHEMT (pseudomorphic >>> high-electron-mobility transistor) and E-pHEMT (enhancement-mode >>> pHEMT), we got inexpensive discrete parts like Avago's ATF-38143, >>> a 10GHz 4-volt 200mA FET in a convenient 4-lead SC-70 package. >> >> Small suggestion: Mentioning e-pHEMT right next to the ATF-38143, >> which is a depletion-mode part seems a bit suboptimal. Maybe just >> leave out the e/d distinction altogether? >> >> &Acirc;&nbsp;&acirc;&euro;&rdquo; David > > RIP.
Yes, I noticed that issue, will re-write a few sentences. -- Thanks, - Win
Reply by Phil Hobbs July 29, 20192019-07-29
On 7/29/19 9:13 AM, David Nadlinger wrote:
> On 28.07.19 2:18 PM, Winfield Hill wrote: >> With technologies like pHEMT (pseudomorphic >> high-electron-mobility transistor) and E-pHEMT (enhancement-mode >> pHEMT), we got inexpensive discrete parts like Avago's ATF-38143, >> a 10GHz 4-volt 200mA FET in a convenient 4-lead SC-70 package. > > Small suggestion: Mentioning e-pHEMT right next to the ATF-38143, which > is a depletion-mode part seems a bit suboptimal. Maybe just leave out > the e/d distinction altogether? > > &Acirc;&nbsp;&acirc;&euro;&rdquo; David
RIP. 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
Reply by David Nadlinger July 29, 20192019-07-29
On 28.07.19 2:18 PM, Winfield Hill wrote:
> With technologies like pHEMT (pseudomorphic > high-electron-mobility transistor) and E-pHEMT (enhancement-mode > pHEMT), we got inexpensive discrete parts like Avago's ATF-38143, > a 10GHz 4-volt 200mA FET in a convenient 4-lead SC-70 package.
Small suggestion: Mentioning e-pHEMT right next to the ATF-38143, which is a depletion-mode part seems a bit suboptimal. Maybe just leave out the e/d distinction altogether? &acirc;&euro;&rdquo; David
Reply by Winfield Hill July 28, 20192019-07-28
Klaus Kragelund wrote...
> > I have not had the time to read it through thoroughly, > but I do not see the Spirito effect mentioned:
It's going to get a proper mention. -- Thanks, - Win
Reply by Klaus Kragelund July 28, 20192019-07-28
I have not had the time to read it through thoroughly, but I do not see the Spirito effect mentioned:

https://www.google.com/search?client=safari&channel=iphone_bm&source=hp&ei=1i8-XdiZKoOKrwSf0q4I&q=spirito+effect&oq=spirito+eff&gs_l=mobile-gws-wiz-hp.1.0.0l2j0i22i30l6.9576.15921..16887...0.0..0.164.1147.10j3......0....1.......0..46j46i275j0i10.vrrvDa3Mf-g

Cheers 

Klaus