Revised: March 17, 2009
73
© 2009 Littelfuse, Inc.
Specications are subject to change without notice.
Surface Mount Fuses
443 Series
NANO2® > 250V > Time Lag > 443 Series
Please refer to www.littelfuse.com/series/443.html for current information.
443 Series
443 Series Fuse
Description
Agency Approvals
Electrical Characteristics for Series
Features
t 7"$WPMUBHFSBUJOH
t 5JNF-BH
t "WBJMBCMF"o
"
t 3P)4$PNQMJBOU
t 'VMMZDPNQBUJCMF
XJUIMFBEGSFFTPMEFS
BMMPZTBOEIJHIFS
UFNQFSBUVSFQSPåMFT
BTTPDJBUFEXJUIMFBE
GSFFBTTFNCMZ
% of Ampere
Rating Opening Time
 IPVST.JOJNVN
 TFDPOET.BYJNVN
AGENCY AGENCY FILE NUMBER AMPERE RANGE
E10480 0.500A - 5.00A
Electrical Specications by Item
Ampere
Rating
(A)
Amp Code
Max
Voltage
Rating
(V)
Interrupting
Rating
Nominal Cold
Resistance
(Ohms)
Nominal
Melting
It (A2sec)
Nominal
Voltage Drop
(mV)
Agency
Approvals
  
"!7"$
  448 Y
      Y
1     Y
      Y
     Y
      Y
    Y
     98 Y
4    81 Y
     Y
Notes:
1. Cold resistance measured at less than 10% of rated current at 23°C.
2. Agency Approval Table Key: X=Approved or Certied, P=Pending and Blank=Not Approved
3. Have special electrical characteristic needs? Contact Littelfuse to learn more about application specic options.
5IF7/BOP'VTFJTBTNBMMTRVBSFTVSGBDFNPVOU
GVTFUIBUJTEFTJHOFEUPFOBCMFDPNQMJBODFXJUIUIF3P)4
EJSFDUJWF5IJTQSPEVDUJTGVMMZDPNQBUJCMFXJUIMFBEGSFF
TPMEFSBMMPZBOEIJHIFSUFNQFSBUVSFQSPåMFTBTTPDJBUFE
XJUIMFBEGSFFBTTFNCMZ
Applications
t "$%$QPXFSBEBQUPS
t 5FMFDPNFRVJQNFOU
TZTUFNQPXFS
t 1PSUBCMFTZTUFNCVJMU
JO"$%$DPOWFSUFS
t )JHIWPMUBHF%$%$
DPOWFSUFS
t -JHIUJOH4ZTUFN
t -&%-JHIUJOH
Revised: March 17, 2009
Introduction to Circuit Protection
Introduction to Circuit Protection
Transientology
74 © 2009 Littelfuse, Inc.
Specications are subject to change without notice.
Surface Mount Fuses
443 Series
NANO2® > 250V > Time Lag > 443 Series
Please refer to www.littelfuse.com/series/443.html for current information.
Average Time Current Curves
Reow Condition 1Co'SFFBTTFNCMZ
Pre Heat
- Temperature Min (Ts(min))¡$
- Temperature Max (Ts(max))¡$
- Time (Min to Max) (ts)oTFDT
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) ¡$
- Temperature (tL)oTFDPOET
Peak Temperature (TP)¡$
Time within 5°C of actual peak
Temperature (tp)oTFDPOET
Ramp-down Rate ¡$TFDPOENBY
Time 25°C to peak Temperature (TP)NJOVUFTNBY
Do not exceed ¡$
Soldering Parameters
Temperature Rerating Curve
0.001
0.01
0.1
1
10
10 0
0.1 1 10 100 1000
TIME IN SECONDS
CURRENT IN AMPS
0.50 A
0.75 A
1.00 A
1.50 A
2.00 A
2.50 A
3.00 A
3.50 A
4.00 A
5.00 A
/PUF
 %FSBUJOHEFQJDUFEJOUIJTDVSWFJTJOBEEJUJPOUPUIFTUBOEBSEEFSBUJOHPGGPS
DPOUJOVPVTPQFSBUJPO
Wave Soldering Parameters
¡$1FBL
5FNQFSBUVSF
TFDPOETNBY
Time
Temperature
TP
TL
TS(max)
TS(min)
25
tP
tL
tS
time to peak temperature
(t 25ºC to peak)
Ramp-down
Ramp-up
Preheat
Critical Zone
TL to TP
Revised: March 17, 2009
75
© 2009 Littelfuse, Inc.
Specications are subject to change without notice.
Surface Mount Fuses
443 Series
NANO2® > 250V > Time Lag > 443 Series
Please refer to www.littelfuse.com/series/443.html for current information.
443 Series
Materials #PEZ$FSBNJD
$BQ4JMWFS1MBUFE#SBTT
Product Marking
#PEZ#SBOE-PHP$VSSFOU3BUJOH
3BUFE7PMUBHF5$
$IBSBDUFSJTUJDi5w
Insulation Resistance
BGUFS0QFOJOH
.*-45%.FUIPE
5FTU$POEJUJPO"PINT
.JOJNVN
Solderability .*-45%.FUIPE
Resistance to
Soldering Heat
.*-45%.FUIPE
5FTU$POEJUJPO#TFDBUP$
Moisture Sensitivity
Level -FWFM+45%$
PCB
Recommendation
for Thermal
Management
.JODPQQFSMBZFSUIJDLOFTTVN
.JODPQQFSUSBDFXJEUINN
"MUFSOBUFNFUIPETPGUIFSNBMNBOBHF
NFOUNBZCFVTFE*OTVDIDBTFT
VOEFSOPSNBMPQFSBUJPOTUIFNBYJNVN
UFNQFSBUVSFPGUIFGVTFCPEZTIPVME
OPUFYDFFE0$JOB0$BNCJFOU
FOWJSPONFOU
Product Characteristics
5A 3.12
(.123")
3.12
(.123")
10.10
(.397")
3.25
(.128")
3.43
(.135")
12.6
(.496")
6.10
(.240")
Recommended Pad Layout
1.70 typ
(.067")
AC250V
T
Dimensions
Packaging
Part Numbering System
Packaging Option Packaging Specication Quantity Quantity &
Packaging Code
NN5BQFBOE3FFM &*"34*&$QBSU  %3
Operating Temperature o0$UP0$XJUIQSPQFSEFSBUJOH
Thermal Shock
.*-45%'.FUIPE(
5FTU$POEJUJPO#DZDMFTP$
UPP$
Vibration .*-45%'.FUIPE"
)[
Moisture Resistance
.*-45%.FUIPE
)JHI)VNJEJUZ3))FBU
P$
Salt Spray .*-45%'.FUIPE
5FTU$POEJUJPO#
Mechanical Shock
.*-45%.FUIPE
5FTU$POEJUJPO*(TQFBLGPS
NJMMJTFDPOET
0443 .500 D R
SERIES
AMP Code
QUANTITY Code
PACKAGING Code
3FGFSUP&MFDUSJDBM
DIBSBDUFSJTUJDTUBCMF
%QDT
35BQFBOE3FFM
Example:
BNQQSPEVDUJT
01.5 %3BNQ
QSPEVDUTIPXOBCPWF
Revised: March 17, 2009
Introduction to Circuit Protection
Introduction to Circuit Protection
Transientology
76 © 2009 Littelfuse, Inc.
Specications are subject to change without notice.