Spehro said:
Hi, all:-
would appreciate recommendations for books on designing electronics to
live in relatively high radiation space environments (not quite
rad-hard). Particularly power MOS circuits and digital.
I don't know about books, but here are some hints. Radiation damage
in bipolar transistors results in a reduction of Hfe, initially at
low collector currents (<100 uA). Hfe decay as a function of dose
is apparently exponential, with a decay constant of about 700 Gy
for small-signal transistors like the 2n2222 for example.
FETs suffer a threshold voltage change. I have no quantitative
data on hand.
The obvious message in discrete designs is to allow for large
changes in these parameters.
In integrated circuits, you have no control over these things.
Old chips, with only NPN transistors, are fairly resistant, and
continue to function, more or less, up to several kGy. Watch out
for devices with lateral PNP transistors, like, say, an LM337
regulator. That one dies with less than 30 Gy. Modern fast TTL
logic likewise dies from a few tens of Grays, whereas old-fashioned
LS or S series survive kGy doses with ease. ECL, at least the
old Motorola 10k and 100k families, is very good, surviving to
10 kGy and beyond. I have no data for the newer series yet.
A whole other subject is Single Event Upsets, where a FF in a
logic circuit may get flipped by a passing particle. There are
design methods based on redundancy and voting that make logic
more robust. I have no experience in the matter. I tend to keep
logic subjected to radiation very simple, and rewrite the whole
register space repetitively from a remote location, so that any
SEU errors get wiped out every second or so.
There are a few web sites that contain some information about
radiation effects in electronics:
The ESA radiation effects website:
https://escies.org/ReadArticle?docId=227
JPL/NASA used to have something similar, but the link I have,
http://radnet.jpl.nasa.gov/compend.htm, is dead. Maybe you can
find it again, if it still exists somewhere.
Slides from a course about radiation effects in semiconductors,
given here at CERN by Martin Dentan in April 2000:
http://rd49.web.cern.ch/RD49/MaterialRadCourse/mdentan1.pdf
The web pages from the radiation working group here. Not sure
if these are accessible from outside CERN. Anyway, here it is:
http://lhc-radwg.web.cern.ch/LHC-radwg/
Hope that helps a bit.
Regards,
Jeroen Belleman