h ps:// adnex .web.ce n.ch/
h ps://www.linkedin.com/company/ adnex
EDMS NO.
3337058
VALIDITY
Released
REV.
1.0
DOI: 10.5281/zenodo.17287822
RADNEXT T ansna ional Access Summa y Repo
P ojec i le
Radia ion Ha dened LCL o Space Applica ions (PSWCITAR)
P ojec TA iden i ie
TA07-191
Gene al applica ion
Space
Type o es
TID, SEE
G oup leade , Ins i u e
Saulo Finco, Cen e o In o ma ion Technology Rena o A che
– CTI.
Co-au ho s, Ins i u es
Agnaldo Viei a Dias and Síl io Manea, B azilian Na ional
Ins i u e o Space Resea ch - INPE.
Ronald Hassib Gal is Chacón, Cen e o In o ma ion
Technology Rena o A che – CTI.
Da e(s) o he expe imen
29/08/2024 – 02/09/2024
Facili y
TRIUMF – UBC - Canada
Amoun o access g an ed
24h
Objec i es o he expe imen s
A La ching Cu en Limi e (LCL) is a c ucial componen in sa elli e powe dis ibu ion sys ems, ac ing
as an "in elligen swi ch". I s p ima y unc ion is o p o ec he dis ibu ion sys ems and elec onic loads
om cu en anomalies, such as hose caused by Single E en La ch-up (SEL). When an o e -cu en
is de ec ed, he LCL i s limi s he cu en o a p ede ined sa e alue (ILimi ) o a speci ic " ip-o " ime
(ToT). I he anomaly pe sis s beyond his ime, he LCL isola es he aul y load. LCLs a e i al in space
applica ions because he adia ion en i onmen can cause SELs, whe e semiconduc o de ices d aw
abno mally high cu en s, po en ially leading o mal unc ion o pe manen damage. Unlike adi ional
uses which a e i e e sible, LCLs can au oma ically ese o powe cycle he a ec ed sys em,
enhancing eliabili y and ex ending he ope a ional li e ime o c i ical componen s.
An LCL was designed wi h bo h he con ol ci cui y and he powe ansis o in eg a ed using 0.6 µm
SOI (Silicon-on-Insula o ) echnology. I s p ima y cha ac e is ic lies in he implemen a ion o a obus
se o Radia ion Ha dened by Design (RHBD) echniques, aiming o signi ican ly enhance i s ole ance
o adia ion en i onmen s. Speci ically, he LCL employs basic cells cons uc ed wi h Enclosed Layou
T ansis o s (ELT). This is c ucial, as he ELT geome y elimina es d ain- o-sou ce leakage cu en s ha
would be caused by cha ge accumula ion in he "bi d's beak" egion in s anda d ansis o s, he eby
con e ing g ea e obus ness o he ci cui s agains cumula i e adia ion e ec s. Complemen a ily,
edundancy was applied o each de ice (s anda d PMOS and NMOS ansis o s om he P ocess
Design Ki - PDK), consis ing o a se ies/pa allel con igu a ion o ou ELT ansis o s o each ansis o .
This echnique was adop ed wi h he cen al objec i e o educing sensi i i y o Single E en E ec s
(SEE). Fu he mo e, he SOI echnology was selec ed o elimina e Single E en La chup (SEL) e ec s
in he con ol ci cui s, due o subs a e isola ion.
EDMS 3337058 .1 s a us In Wo k access Res ic ed
PDF om TA07_191-Zenodo.docx modi ied 2025-10-07 15:41
h ps:// adnex .web.ce n.ch/
h ps://www.linkedin.com/company/ adnex
EDMS NO.
3337058
VALIDITY
Released
REV.
1.0
In he pas , he LCL swi ch was es ed o o al ionizing dose using a Cobal -60 sou ce, whe e i
demons a ed esilience up o se e al hund ed k ad. Tes s we e also conduc ed using hea y ions
(oxygen, chlo ine, and coppe ) o assess he LCL's suscep ibili y o Single-E en E ec s (SEE). In he
es pe o med, he swi ch showed obus ness; howe e , he ene gy le els o he es acili y we e limi ed
(oxygen – 43.5 MeV; chlo ine – 63 MeV; coppe – 84 MeV), which p e en ed ull explo a ion o he LCL’s
limi s.
The main goal was o e i y he unc ionali y o LCL unde i adia ion condi ions, ensu ing p ope
ope a ion as speci ied. The objec i e o he expe imen was o es he beha io o he LCL using high-
ene gy p o ons (480 MeV) a di e en lux le els o e alua e ci cui pe o mance and obus ness, aiming
o obse e he occu ence o SEE. The expe imen was also used o e i y he beha io o he LCL when
subjec ed o high dose a es (100 k ad/h). These accele a ed o al ionizing dose e ec s we e pa icula ly
ele an in he in e nal e e ences o he LCL swi ch con olle .
Di e en e e ences a e essen ial in he powe swi ch sys em p ima ily because he a ious in e nal sub-
ci cui s equi e di e en ol age biasing le els o hei p ope ope a ion. Speci ically, he sys em
inco po a es h ee dis inc e e ences: Reg_5V, Reg_5VUP, and cu en limi ing e e ence. The
unde s anding o TID in luence on hese e e ences a e c ucial o imp o e he pe o mance o he LCL
swi ch.
Expe imen es epo
The LCL is designed o ope a e wi h an inpu ol age (VIN) anging om 22 V o 36 V and a maximum
limi ing cu en (ILimi ) o 6 A. The need o ol age egula o s wi hin he s uc u e is c i ical because,
al hough he sys em inpu ol age a ies ac oss a high- ol age ange (22 V o 36 V), he LCL's in e nal
con ol ci cui s a e p edominan ly implemen ed wi h low- ol age (LV) de ices ha suppo only up o 5V.
Consequen ly, he sys em gene a es wo egula ed 5 V ol ages: one e e enced o GND (V5), essen ial
o biasing he con ol logic and eleme y ci cui s, and ano he ied o VIN (V5UP), u ilized o biasing he
eedback loop ha con ols he pass ansis o . Figu e 1 shows he es boa d and Figu e 2 highligh s he
con olle and powe ansis o o he LCL, bo h implemen ed using RHBD echniques.
Figu e 1 – Tes boa d o LCL swi ch
h ps:// adnex .web.ce n.ch/
h ps://www.linkedin.com/company/ adnex
EDMS NO.
3337058
VALIDITY
Released
REV.
1.0
Ini ially, 33 boa ds we e assembled and iden i ied (Figu e 3). The LCLs we e calib a ed o ensu e
consis en alues o ILimi (6 A) and ToT (2 ms) ac oss all uni s. Addi ionally, bo h egula o s we e
p ecisely adjus ed o main ain a nominal ou pu ol age o 5 V on e e y boa d. Two boa ds we e chosen
as “con ol g oup” and we e no in ended o be exposu e o adia ion.
Figu e 2 – Con olle and powe ansis o o LCL swi ch
Figu e 3 – Assembled and iden i ied boa ds o es ing
• Tes bench se up
To p ope ly check he beha io o he LCL ci cui and i s suscep ibili y o hea y ions, a es se up is
necessa y. To pe o m his ask, an au oma ed es bench has been de eloped. The need o au oma ion
a ises om he a ious es condi ions, which can be a ime-consuming p ocess and he impossibili y o
conduc manual es s du ing adia ion exposu e.
The au oma ed es se up was designed o conduc ing es s on LCLs. The co e o his es en i onmen
is a compu e unning NI Lab iew, which con ols and moni o s he de ices h ough sc ip s de eloped
speci ically o his pu pose. The ins umen a ion includes an oscilloscope wi h a cu en p obe o cu en
h ps:// adnex .web.ce n.ch/
h ps://www.linkedin.com/company/ adnex
EDMS NO.
3337058
VALIDITY
Released
REV.
1.0
measu emen s, a DC elec onic load u ilizing, a DC powe supply, and a da a acquisi ion boa d o con ol
he LCL and ead analog and digi al signals. Ano he compu e was used o moni o he expe imen om
ou side he oom. Figu e 4 shows he es bench se up. The equipmen on he blue olley was placed
inside he beam oom and compu e (Ou side compu e ) was placed in he con ol oom.
All ha equipmen is in e connec ed, o ming an in eg a ed es bench. Du ing es s, he sys em
con inuously moni o s he LCL's ou pu cu en , while he elec onic load pe iodically applies sho ci cui s.
Sho ci cui s a e gene a ed e e y 50 ms wi h a du a ion o 400 us, wi h he cu en se o 1 A o he
emainde o he ime. A es mask was c ea ed o e i y i he swi ch main ains cu en con ol du ing he
sho ci cui s, adhe ing o his mask. This es mask can be seen in Figu e 5. The es bench also checks
i , du ing he in e als whe e cu en limi a ion is no in ope a ion, he swi ch's conduc ion loss s ays wi hin
de ined limi s. I any limi s a e iola ed, he ailu e wa e o m is sa ed, and a mask ailu e coun e is
inc emen ed.
One possible adia ion e ec on he LCL swi ch is i s shu down due o pa icle incidence. I he swi ch
u ns o du ing he es , he se up a emp s o es a i . I he swi ch esumes ope a ion, he es
con inues, and a swi ch shu down coun e is inc emen ed. I he swi ch u ns o , and he es se up ails
o es a he LCL a e h ee a emp s, he es is e mina ed. The es se up can moni o and e i y masks
o 90% o he swi ch's adia ion exposu e ime, meaning ha in 10% o he ime, e en s o his na u e
may be missed. Shu down e en s a e con inuously moni o ed. Fu he mo e, some signals om he
con olle , such as ol age e e ences and cu en consump ion, a e measu ed and s o ed o check i he
swi ch is unde going any changes in i s ope a ing poin .
Fo adia ion es s, conc e e blocks and o he ma e ials we e employed o p o ec he measu emen
ins umen s om he adia ion sou ce (Figu e 6) and only he LCL boa d was exposed o he beam.
• The adia ion es issues
The es s we e scheduled o Augus 29 h wi h a s a ime o 14:00 (12 hou s o du a ion) and Sep embe
2nd wi h a s a ime o 8:30 (12 hou s o du a ion). The es se up was placed in he beam oom, he LCL
boa d was p ope ly posi ioned and he es was s a ed. Howe e , a e a ew hou s, he au oma ed se up
s opped unc ioning due o a c ash o he compu e loca ed inside he beam oom, which was con olling
he expe imen . A new compu e was con igu ed o use in he es se up, and he es was es a ed. In
less han an hou , he se up s opped wo king again. I was concluded ha he adia ion le el inside he
beam oom was oo high and was in e e ing wi h he es se up.
The es s we e hal ed, and a new con igu a ion was assembled. In his new se up, all equipmen was
placed ou side he beam oom, and only he boa d unde es emained inside. A e his modi ica ion,
he es se up ope a ed no mally un il he end o he es pe iod.
Due o he need o modi y he es se up, we los beam ime du ing he ini ially alloca ed pe iod. Howe e ,
he lab s a kindly allowed us o use he acili y du ing ime slo s when no o he use s we e scheduled.
In o al, mo e han 33 hou s o es ing we e pe o med on he LCL swi ches.
h ps:// adnex .web.ce n.ch/
h ps://www.linkedin.com/company/ adnex
EDMS NO.
3337058
VALIDITY
Released
REV.
1.0
Figu e 4 – Au oma ed es bench se up
Figu e 5 – Tes mask showing a ailu e
Figu e 6 – Tes se up p o ec ed using conc e e blocks and o he ma e ials
h ps:// adnex .web.ce n.ch/
h ps://www.linkedin.com/company/ adnex
EDMS NO.
3337058
VALIDITY
Released
REV.
1.0
• Tes esul s and discussion
In he es s, 16 swi ches we e exposed o he beam, while wo o he s we e used as con ol samples. The
main objec i e o he es was o e i y he immuni y o he LCL swi ch o Single-E en E ec s (SEE).
Th oughou all hese es s, whe e he lux a ied be ween 10⁷ pa icles/cm2/s and 10⁹ pa icles/cm2/s and
luences exceeded 10¹¹ pa icles/cm2, no SEE was obse ed, con i ming he obus ness o he swi ch
unde p o on bomba dmen .
The accele a ed o al ionizing dose e ec s we e es ed in six boa ds (B1, B2, B3, B4, B5 e B6) and he
applied TID was 100 k ad(Si). E ec s we e obse ed in he in e nal e e ences o he LCL swi ch
con olle . The es esul s o he Reg_5V e e ence a e p esen ed in Figu e 7, wi h he alues no malized
o acili a e compa ison. Du ing i adia ion, he e e ence ol ages ac oss he di e en boa ds exhibi ed
no uni o m beha io . Some boa ds showed an inc ease in ol age (e.g., boa d B6), while o he s
expe ienced a dec ease (e.g., boa d B5), and he emaining boa ds (B1, B2, B3, and B4) showed
luc ua ions a ound he ini ial ol age le el. The maximum obse ed a ia ion was app oxima ely 5%, and
on a e age (black cu e in Figu e 7), he alues emained ela i ely close o hei ini ial le els. No
signi ican eco e y was obse ed in he e e ence ol ages a e he annealing pe iod.
Figu e 7 - Tes esul s o e e ences o Reg_5V
Figu e 8 shows he no malized es esul s o he Reg_5VUP e e ences. Du ing i adia ion, he e e ence
ol ages ac oss he boa ds exhibi ed a no iceable end, e en on a e age (black cu e in Figu e 8).
Ini ially, a dec ease in ol age was obse ed, con inuing up o a ound 35 k ad. A e his poin , he alues
began o inc ease, su passing he ini ial ol age nea 60 k ad. Towa d he end o he i adia ion, a
sa u a ion e ec was obse ed. Following he annealing pe iod, a s ong eco e y in he e e ence
ol ages occu ed, wi h he inal alues s abilizing a app oxima ely 90% o he o iginal le el.
Figu e 9 p esen s he no malized es esul s o he cu en limi ing e e ences. Du ing i adia ion, he
e e ence ol ages ac oss all boa ds exhibi ed a clea and consis en downwa d end. Vol age educ ions
we e obse ed om he beginning o he exposu e, wi h no pe iods o eco e y h oughou he es .
Towa d he end o he i adia ion (a e 90 k ad), a sa u a ion e ec appea s o occu . The maximum
ol age educ ion eached app oxima ely 10%, while he a e age dec ease ( ep esen ed by he black
cu e in Figu e 9) was a ound 7%. No signi ican eco e y was obse ed in he e e ence ol ages a e
he annealing pe iod.
h ps:// adnex .web.ce n.ch/
h ps://www.linkedin.com/company/ adnex
EDMS NO.
3337058
VALIDITY
Released
REV.
1.0
I was obse ed ha he ol age e e ence used in he Reg_5V was he mos s able du ing he es s, wi h
a maximum a ia ion close o 5% and an a e age a ia ion ha was i ually ze o. The o he e e ences
showed g ea e a ia ions du ing he es s and, a e he annealing pe iod, did no e u n o hei ini ial
alues, exhibi ing a pe manen change in hei beha io . Despi e he a ia ions in elec ical pa ame e s,
all i adia ed boa ds emained unc ional a e he adia ion es s.
A u u e s udy should be conduc ed o in es iga e he eason o he di e en le els o deg ada ion
obse ed among he a ious e e ence ci cui s when subjec ed o i adia ion. Unde s anding he adia ion
in e ac ion mechanisms in di e en opologies will enable he design o mo e adia ion- esis an
e e ences, esul ing in mo e eliable ci cui s o use in space missions.
Figu e 8 - Tes esul s o e e ences o Reg_5VUP
Figu e 9 - Tes esul s o e e ences o cu en limi ing
h ps:// adnex .web.ce n.ch/
h ps://www.linkedin.com/company/ adnex
EDMS NO.
3337058
VALIDITY
Released
REV.
1.0
• Conclusion
I was obse ed ha he LCL design was esilien and had no issues conce ning SEE. These esul s also
p o ide a p elimina y alida ion o he p oposed RHBD echnique, which consis s o a se ies/pa allel
con igu a ion o ou ELT ansis o s o each ansis o . Also, i was obse ed he ol age e e ence used
in he Reg_5V was he mos s able du ing he es s, wi h a maximum a ia ion close o 5% and an a e age
a ia ion ha was i ually ze o. The o he e e ences showed g ea e a ia ions du ing he es s and,
a e he annealing pe iod, did no e u n o hei ini ial alues, exhibi ing a pe manen change in hei
beha io . Despi e he a ia ions in elec ical pa ame e s, all i adia ed boa ds emained unc ional a e
he adia ion es s.
A u u e s udy should be conduc ed o in es iga e he eason o he di e en le els o deg ada ion
obse ed among he a ious e e ence ci cui s when subjec ed o i adia ion. Unde s anding he adia ion
in e ac ion mechanisms in di e en opologies will enable he design o mo e adia ion- esis an
e e ences, esul ing in mo e eliable ci cui s o use in space missions.
Ou come o he expe imen s
Please indica e wha he expe imen is likely o lead o by pu ing an ‘X’ nex o one o mo e o he
possible ou comes below.
Jou nal publica ion
X
Da a o Thesis
X
Follow-up expe imen a same acili y
Follow-up expe imen a ano he acili y
X
O he
As a RADNEXT use , we encou age you o submi he scien i ic esul s o you expe imen s o jou nals
as well as o he NSREC and RADECS da a wo kshops. Please emembe o include he RADNEXT
acknowledgmen in o you publica ions!
RADNEXT acknowledgmen :
This p ojec has ecei ed unding om he Eu opean Union's Ho izon 2020
esea ch and inno a ion p og amme unde g an ag eemen No 101008126.
