61
© 2009 Littelfuse, Inc.
Specications are subject to change without notice.
Surface Mount Fuses
452/454 Series
NANO2® > Slo-Blo® > 452/454 Series
452/454 Series
Please refer to www.littelfuse.com/series/452.html
or /454.html for current information.
452/454 Series Fuse
Description
The NANO2 Slo-Blo® fuse has enhanced inrush withstand
characteristics over the NANO2 Fast-Acting fuse. The
unique time delay feature of this fuse design helps solve
the problem of nuisance “opening” by accommodating
inrush currents that normally cause a fast-acting fuse to
open.
Features
t 5JNF-BH4MP#MP
t 4NBMMTJ[F
t 8JEFSBOHFPGDVSSFOU
SBUJOHBWBJMBCMFN"
UP"
t 8JEFPQFSBUJOH
temperature range
t -PXUFNQFSBUVSF
de-rating
t 3P)4DPNQMJBOU
t )BMPHFO'SFF
Electrical Characteristics for Series
% of Ampere
Rating Opening Time
100% 4 hours, Minimum
200% 1 sec., Min.; 60 sec., Max.
 TFD.JOTFD.BY
800% 0.02 sec., Min.; 0.1 sec., Max.
PS
E
Electrical Specications by Item
Ampere
Rating
(A)
Amp Code
Max
Voltage
Rating
(V)
Interrupting
Rating
Nominal Cold
Resistance
(Ohms)
Nominal
Melting
I2t (A2sec)
Agency Approvals
PS
E
  
BNQFSFT!7"$7%$
BNQFSFT!7%$
14&BNQFSFT!7"$
1.2000 0.101 x x
    0.240 x x
    0.904 x x
001. 001.   1.98 x x x
     xxx
2.00 002.   8.20 x x x
     xxx
    20.16 x x x
   0.0224  xxx
4.00 004.  0.0186  xxx
     xxx
  BNQFSFT!7"$
BNQFSFT!7%$   xx
8 008.  BNQFSFT!7"$
BNQFSFT!7%$
0.0088  xx
12 012.  0.0061 260.46 x x
Applications
t /PUFCPPL1$
t -$%1%157
t -$%NPOJUPS
t -$%1%1QBOFM
t -$%CBDLMJHIUJOWFSUFS
t 1PSUBCMF%7%QMBZFS
t 1PXFSTVQQMZ
t /FUXPSLJOH
t 1$TFSWFS
t $PPMJOHGBOTZTUFN
t 4UPSBHFTZTUFN
t 5FMFDPNTZTUFN
t 8JSFMFTTCBTFTUBUJPO
t 8IJUFHPPET
t (BNFDPOTPMF
t 0GåDF"VUPNBUJPO
equipment
t #BUUFSZDIBSHJOHDJSDVJU
protection
t *OEVTUSJBMFRVJQNFOU
t .FEJDBMFRVJQNFOU
t "VUPNPUJWF
Agency Approvals
AGENCY AGENCY FILE NUMBER AMPERE RANGE
E10480 375mA - 12A
LR29862 375mA - 12A
PS
ENBK030205-E10480B 1A - 5A
Notes:
- l2t calculated at 8ms.
- Resistance is measured at 10% of rated current, 25ºC
Revised: May 3, 2011
Introduction to Circuit Protection
Introduction to Circuit Protection
Transientology
62 © 2009 Littelfuse, Inc.
Specications are subject to change without notice.
Surface Mount Fuses
452/454 Series
NANO2® > Slo-Blo® > 452/454 Series
Please refer to www.littelfuse.com/series/452.html
or /454.html for current information.
Average Time Current Curves
Reow Condition Pb – Free assembly
Pre Heat
- Temperature Min (Ts(min))¡$
- Temperature Max (Ts(max))¡$
- Time (Min to Max) (ts)60 – 120 secs
Average ramp up rate (Liquidus Temp
(TL) to peak ¡$TFDPOENBY
TS(max) to TL - Ramp-up Rate ¡$TFDPOENBY
Reow - Temperature (TL) (Liquidus) ¡$
- Temperature (tL)60 – 90 seconds
Peak Temperature (TP)¡$
Time within 5°C of actual peak
Temperature (tp)20 – 40 seconds
Ramp-down Rate ¡$TFDPOENBY
Time 25°C to peak Temperature (TP)8 minutes max.
Do not exceed ¡$
Wave Soldering Parameters
¡$1FBL
Temperature,
TFDPOETNBY
Soldering Parameters
Temperature Rerating Curve
Note:
 %FSBUJOHEFQJDUFEJOUIJTDVSWFJTJOBEEJUJPOUPUIFTUBOEBSEEFSBUJOHPGGPS
continuous operation.
Time
Temperature
TP
TL
TS(max)
TS(min)
25
tP
tL
tS
time to peak temperature
(t 25ºC to peak)
Ramp-down
Ramp-up
Preheat
Critical Zone
TL to TP
0.01
0.1
1
10
100
0.1 1 10 100 1000
TIME IN SECONDS
CURRENT IN AMPS
375mA
500mA
1.00A
1.50A
2.00A
2.50A
3.00A
3.50A
4.00A
5.00A
7.00A
750mA
8.00A
12.0A
63
© 2009 Littelfuse, Inc.
Specications are subject to change without notice.
Surface Mount Fuses
452/454 Series
NANO2® > Slo-Blo® > 452/454 Series
452/454 Series
Please refer to www.littelfuse.com/series/452.html
or /454.html for current information.
Materials
#PEZ$FSBNJD
5FSNJOBUJPOT(PMEQMBUFE$BQT
4JMWFSQMBUFE$BQT
Product Marking #SBOE"NQFSF3BUJOH
Operating
Temperature ¡$UP¡$
Moisture
Sensitivity Level -FWFM+45%$
Solderability .*-45%.FUIPE
Insulation
Resistance (after
Opening)
.*-45%.FUIPE5FTU$POEJUJPO
"PINTNJOJNVN
Thermal Shock
.*-45%.FUIPE5FTU
$POEJUJPO#DZDMFT¡$
¡$NJOVUFT!FBDIFYUSFNF
Mechanical Shock
.*-45%.FUIPE5FTU*
%FFOFSHJ[FE(TQLBNQMJUVEF
TBXUPPUIXBWFNTEVSBUJPO
DZDMFT9:;YZ[TIPDLT
Vibration
.*-45%.FUIPEw
BNQMJUVEF)[JONJOIST
FBDI9:;IST
Moisture Resistance .*-45%.FUIPEDZDMFT
Salt Spray .*-45%.FUIPE5FTU
$POEJUJPO#IST
Resistance to Soldering
Heat
.*-45%.FUIPE5FTU
DPOEJUJPO#TFDBU¡$
Product Characteristics
1 AT
6.86
(.270")
3.15
(.124")
2.95
(.116")
1.96
(.077")
2.69
(.106")
2.69
(.106")
1.45
(.057")
6.10
(.240")
Recommended pad layout
F
Dimensions
Packaging
Part Numbering System
Packaging Option Packaging Specication Quantity Quantity &
Packaging Code
NN5BQFBOE3FFM &*"34*&$QBSU  /3
NN5BQFBOE3FFM &*"34*&$QBSU 1000 .3
0452 001. M R L
SERIES
AMP Code
QUANTITY Code
PACKAGING Code
.QDT
/QDT
35BQFBOE3FFM
RoHS Compliant & Halogen Free
3FGFSUP"NQ$PEFDPMVNOJOUIF
&MFDUSJDBM4QFDJåDBUJPOTUBCMF
The dot is positioned at the end of the
number sequence with whole ratings
and within for fractional ratings.
Example:"NQQSPEVDUJT
.375.3-BNQQSPEVDUTIPXO
NOTE: “L” sufx applies to 452 series only
 TFSJFT NBZ CF PSEFSFE BT FJUIFSi3P)4 BOE )'w i-w TVGåY PS OPO3P)4 OP
TVGåYWFSTJPO
TFSJFTJTBWBJMBCMFPOMZBTi3P)4BOE)'wWFSTJPOBOEEPFTOPUSFRVJSFi-wTVGåY
1MFBTFEPOPUJODMVEFi-wTVGåYXJUIJOTFSJFTPSEFSJOHJOTUSVDUJPOT