Surface Mount Fuses
Introduction to Circuit Protection
Transientology
Thin Film > 0402 Size > Very Fast-Acting > 435 Series
Temperature Rerating Curve
AverageTime Current Curves
100
10
1
0.1
Note:
0.01
1.ꢀ Deratingꢀdepictedꢀinꢀthisꢀcurveꢀisꢀinꢀadditionꢀtoꢀtheꢀstandardꢀderatingꢀofꢀ25%ꢀforꢀ
continuousꢀoperation.
Example:
ꢀ
ꢀ
Forꢀcontinuousꢀoperationꢀatꢀ70ꢀdegreesꢀcelsius,ꢀtheꢀfuseꢀshouldꢀbeꢀderatedasꢀfollows:
Iꢀ=ꢀ(0.75)(0.80)IRATꢀ=ꢀ(0.60)IRAT
0.001
0.1
1.0
10.0
100.0
CURRENT IN AMPERES
2.ꢀTheꢀtemperatureꢀderatingꢀcurveꢀrepresentsꢀtheꢀnominalꢀconditions.ꢀForꢀquestionsꢀ
aboutꢀtemperatureꢀderatingꢀcurve,ꢀpleaseꢀconsultꢀLittelfuseꢀtechnicalꢀsupportꢀ
forꢀassistance.
Soldering Parameters
tP
rꢂflow coꢅdꢄtꢄoꢅ
-Tꢂꢀꢁꢂꢃatꢈꢃꢂ mꢄꢅ (Ts(ꢀꢄꢅ)
Pbꢀ–ꢀFreeꢀassembly
TP
Critical Zone
Ramp-up
TL to TP
)
150°Cꢀ
TL
TS(max)
pꢃꢂ Hꢂat -Tꢂꢀꢁꢂꢃatꢈꢃꢂ max (Ts(ꢀax)
)
200°C
tL
-Tꢄꢀꢂ (mꢄꢅ to max) (ts)
60ꢀ–ꢀ120ꢀsecs
Ramp-down
Avꢂꢃaꢆꢂ ꢃaꢀꢁ ꢈꢁ ꢃatꢂ (lꢄqꢈꢄdꢈsTꢂꢀꢁ
(Tl) to ꢁꢂak
Preheat
5°C/secondꢀmax
TS(min)
tS
TS(ꢀax) toTl - raꢀꢁ-ꢈꢁ ratꢂ
5°C/secondꢀmax
217°Cꢀ
-Tꢂꢀꢁꢂꢃatꢈꢃꢂ (Tl) (lꢄqꢈꢄdꢈs)
rꢂflow
25
time to peak temperature
(t 25ºC to peak)
-Tꢂꢀꢁꢂꢃatꢈꢃꢂ (tl)
60ꢀ–ꢀ150ꢀseconds
250+0/-5ꢀ°C
Time
pꢂakTꢂꢀꢁꢂꢃatꢈꢃꢂ (Tp)
Tꢄꢀꢂ wꢄthꢄꢅ 5°c of aꢉtꢈaꢇ ꢁꢂak
Tꢂꢀꢁꢂꢃatꢈꢃꢂ (tꢁ)
20ꢀ–ꢀ40ꢀseconds
raꢀꢁ-dowꢅ ratꢂ
5°C/secondꢀmax
8ꢀminutesꢀMax.
260°C
Tꢄꢀꢂ 25°c to ꢁꢂakTꢂꢀꢁꢂꢃatꢈꢃꢂ (Tp)
Do ꢅot ꢂxꢉꢂꢂd
Wavꢂ Soꢇdꢂꢃꢄꢅꢆ
260°C,ꢀ10ꢀsecondsꢀmax.
© 2009 Littelfuse, Inc.
435 Series
46
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/435.html for current information.
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