45
© 2009 Littelfuse, Inc.
Specications are subject to change without notice.
Surface Mount Fuses
435 Series
Thin Film > 0402 Size > Very Fast-Acting > 435 Series
Please refer to www.littelfuse.com/series/435.html for current information.
435 Series
435 Series Fuse
Description
Agency Approvals
AGENCY AGENCY FILE NUMBER AMPERE RANGE
E10480 0.250 - 5.0A
LR 29862 0.250 - 5.0A
Electrical Characteristics for Series
Features
• 35Ainterruptratingat
32VDC
• Smallsizewithcurrent
ratingsof0.25to5.0
amperes
• RoHScompliant,lead-
freeandhalogen-free
• Maximumprotection
ofsensitivecircuits
asfusesaredesigned
toopenconsistently
in<5secat200%
overload.
• EnhancedBreaking
Capacity,Highl2t
% of Ampere
Rating
Ampere
Rating Opening Time at 25OC
100% 0.250A-5A 4hours,Minimum
200% 0.375A-5A 5secs.,Maximum
300% 0.250A 5secs.,Maximum
300% 0.375A-5A 0.2sec.,Maximum
Ampere
Rating
(A)
Amp
Code
Max
Voltage
Rating
(V)
Interrupting
Rating
Nominal Cold
Resistance
(Ohms)
Nominal
Melting
I2t (A2sec)
Nom
Voltage
Drop
(mV)
Nom
Power
Dissipation
(W)
Agency Approvals
0.250 .250 32
35A@32VDC
0.2265 0.0025 60.67 0.01517 x x
0.375 .375 32 0.1930 0.0035 84.64 0.03174 x x
0.500 .500 32 0.1600 0.0053 93.35 0.04668 x x
0.750 .750 32 0.1050 0.0120 101.84 0.07638 x x
1.00 001. 32 0.0730 0.0200 87.45 0.08745 x x
1.25 1.25 32 0.0600 0.0350 96.37 0.12046 x x
1.50 01.5 32 0.0470 0.0560 86.70 0.13005 x x
1.75 1.75 32 0.0390 0.0750 81.13 0.14198 x x
2.00 002. 32 0.0300 0.1000 70.62 0.14120 x x
2.50 02.5 32 0.0185 0.1560 55.25 0.13813 x x
3.00 003. 32 0.0165 0.2032 60.58 0.18740 x x
3.50 03.5 32 0.0135 0.3017 57.84 0.20244 x x
4.00 004. 32 0.0115 0.3084 57.00 0.22800 x x
5.00 005. 32 0.0085 0.5310 52.44 0.26220 x x
Electrical Specications by Item
1. Measuredat10%ofratedcurrent,25ºC.
2.Measuredatratedvoltage.
The435Seriesarefast-actingsurfacemountthin-lm
fuses.Theirultra-smallsize(0402size)makesthemidealfor
secondaryprotectionofcircuitsusedinspaceconstrained
applicationssuchashand-heldportableelectronicdevices.
Thisseriesis100%lead-freeandmeettherequirementsof
theRoHSdirective.NewHalogen-Free435Seriesfusesare
available–toorderusethe“HF”sufx.SeePartNumbering
sectionforadditionalinformation.
Applications
• Cellphones
• Batterypacks
• Digitalcameras
• DVDplayers
• Harddiskdrives.
Secondaryprotectionforspaceconstrainedapplications
suchas:
Revised: Jun 16, 2011
Introduction to Circuit Protection
Introduction to Circuit Protection
Transientology
46 © 2009 Littelfuse, Inc.
Specications are subject to change without notice.
Surface Mount Fuses
435 Series
Thin Film > 0402 Size > Very Fast-Acting > 435 Series
Please refer to www.littelfuse.com/series/435.html for current information.
Average Time Current Curves
0.001
0.01
0.1
1
10
100
0.1 1.0 10.0 100.0
TIME IN SECONDS
CURRENT IN AMPERES
1.5A
1.25A
1.75A
2A
2.5A
3A
3.5A
4A
5A
1A
.25A
.375A
.5A
.75A
Reow Condition Pb–Freeassembly
Pre Heat
- Temperature Min (Ts(min))150°C
- Temperature Max (Ts(max))200°C
- Time (Min to Max) (ts)60–120secs
Average ramp up rate (Liquidus Temp
(TL) to peak 5°C/secondmax
TS(max) to TL - Ramp-up Rate 5°C/secondmax
Reow - Temperature (TL) (Liquidus) 217°C
- Temperature (tL)60–150seconds
Peak Temperature (TP)250+0/-5°C
Time within 5°C of actual peak
Temperature (tp)20–40seconds
Ramp-down Rate 5°C/secondmax
Time 25°C to peak Temperature (TP)8minutesMax.
Do not exceed 260°C
Soldering Parameters
Temperature Rerating Curve
Wave Soldering 260°C,10secondsmax.
Note:
1. Deratingdepictedinthiscurveisinadditiontothestandardderatingof25%for
continuousoperation.
Example:
Forcontinuousoperationat70degreescelsius,thefuseshouldbederatedasfollows:
I=(0.75)(0.80)I
RAT
=(0.60)I
RAT
2.Thetemperaturederatingcurverepresentsthenominalconditions.Forquestions
abouttemperaturederatingcurve,pleaseconsultLittelfusetechnicalsupport
forassistance.
Time
Temperature
TP
TL
TS(max)
TS(min)
25
tP
tL
tS
time to peak temperature
(t 25ºC to peak)
Ramp-down
Ramp-up
Preheat
Critical Zone
TL to TP
47
© 2009 Littelfuse, Inc.
Specications are subject to change without notice.
Surface Mount Fuses
435 Series
Thin Film > 0402 Size > Very Fast-Acting > 435 Series
Please refer to www.littelfuse.com/series/435.html for current information.
435 Series
RefertoAmpCodecolumninthe
ElectricalSpecicationstable.
Thedotispositionedattheendofthe
numbersequencewithwholeratings
andwithinforfractionalratings.
Example: 1.5ampproductis
043501.5KRHF(2ampproductshown)
Materials
Body:Epoxy/GlassSubstrate;
Partswith‘HF’sufx:HalogenFreeEpoxy/Glass
Terminations:100%TinoverNickeloverCopper
Device Weight:0.316mg
Terminal
Strength MIL-STD-202F,Method211A,TestConditionA
Insulation
Resistance AfterOpening:Greaterthan10,000Ohms
Operating
Temperature
–55°Cto90°C.
Consulttemperaturereratingcurvechart.
Foroperationabove90°Cpleasecontact
Littelfuse.
Thermal Shock Withstands5cyclesof–55°Cto125°C
Vibration MIL-STD-202F
Product Characteristics
.558
(.022")
Reow solder
recommended
mounting pad
dimensions
.991 +/- .051
(.039" +/- .002")
Marking code varies
with amperage.
Refer to Part Marking
System chart.
Cu
.508 +/- .051
(.020" +/- .002")
.229 +/- .102
(.009" +/- .004")
0.330 +/- .102
(.013" +/- .004")
.381
(.015") 1.55
(.061")
.584
(.023")
0.292 +/- .102
(.012" +/- .004")
.2159 +/- .0889
(.0085" +/- .0035")
Sn
A
B
C
D
Dimensions
Packaging
Part Numbering System
Part Marking System
Packaging Option Packaging Specication Quantity Quantity &
Packaging Code
8mmTapeandReel EIA-481Rev.D(IEC60286,part3) 10000 KR
A B C D
inchmin 0.037 0.018 0.008 0.005
inchmax 0.041 0.022 0.016 0.012
mmmin 0.94 0.457 0.190 0.127
mmmax 1.04 0.559 0.394 0.305
0435 002. K R HF S
SERIES
AMP Code
HALOGEN FREE ITEM
“S” - for .250A only
PACKAGING Code
R=TapeandReel
QUANTITY Code
K=10,000Pieces
Amp
Code
Marking
Code
.250
.375
.500
.750
001.
1.25
01. 5
1.75
002.
02.5
003.
03.5
004.
005.
X