[time-nuts] Re: +1/f of transistors

[Lux, Jim]

On 4/2/22 3:31 AM, Leon Pavlovic wrote:
> Hello to all,
>
> as Gerhard already mentioned, the 1/f data of transistors is really a
> kind-of black magic stuff and almost never present in the datasheets.

Not only that, but it potentially changes from lot to lot.

Lately, I've been seeing papers using various microwave pHEMTs but, by 
the time you find and read the paper, the part is no longer available. 
And, of course, just like low noise MMICs (PGA-103, GALI-74) you have to 
measure them yourself to find out - because the mfr only measures from 
50 MHz and up.

A good example is the 2018 paper by Chen, et al. which references the 
ATF54143 - a 3 year old paper, and the part isn't available any more.  
The 2SK117 shows up a lot in some older articles and app notes (e.g. 
from Wenzel) - it's discontinued, but potentially available from some 
surplus/obsolete dealers.

Exp Astron (2018) 45:231–253 https://doi.org/10.1007/s10686-018-9576-3 
https://link.springer.com/article/10.1007/s10686-018-9576-3


There is a list in The Art of Electronics, but some of them won't be 
available.   Some datasheets do have the curve - the JFE150 from TI has 
its voltage noise curve right on the front page.