© 2012 Littelfuse, Inc.
Specifications are subject to change without notice.
Axial Lead & Cartridge Fuses
251/253 Series
Please refer to www.littelfuse.com/series/251.html
or /253.html for current information.
PICO
®
ll > Very Fast-Acting > 251/253 Series
251/253 Series
Revised: September 6, 2012
251/253 Series, PICO
®
II, Very Fast-Acting Fuse
Description
The PICO
®
II Very Fast-Acting Fuse is designed to meet an
extensive array of performance characteristics in a
space-saving subminiature package.
Agency Approvals
Agency Agency File Number Ampere Range
E10480 62mA - 15A
LR 29862 62mA - 15A
PS
E
JET 1896-31007-1001 1A - 5A
TUV
J50158379 500mA - 10A
QP
FM10 62mA - 15A
2009010207366577 –
500mA to 5A
500mA, 1A, 2A, 2.5A,
3A, 4A, 5A
Features
Electrical Characteristics for Series
% of Ampere
Rating
Ampere Rating Opening Time
100% 62mA - 15A 4 Hours, Min.
20
0%
62mA - 7A 1 Second, Max.
10A 3 Seconds, Max.
12 - 15A 10 Seconds, Max.
275%
500mA, 1A, 2A,
2.5A, 3A, 4A, 5A,
7A, 10A
300 msecs., Max.
400%
500mA, 1A, 2A,
2.5A, 3A, 4A, 5A,
7A, 10A
30 msecs., Max.
1000%
500mA, 1A, 2A,
2.5A, 3A, 4A, 5A,
7A, 10A
4 msecs., Max.
Applications
PS
E
t 'MBUoQBOFMEJTQMBZ57
t -$%NPOJUPS
t -$%CBDLMJHIUJOWFSUFS
t 0GmDFNBDIJOFT
t 1PXFSTVQQMZ
t "VEJP7JEFPTZTUFN
t -JHIUJOHTZTUFN
t .FEJDBMFRVJQNFOU
4FDPOEBSZQSPUFDUJPOGPSTQBDFDPOTUSBJOFEBQQMJDBUJPOT
TUV
QP
t 7FSZGBTUBDUJOH
t 4NBMMTJ[F
t 8JEFDVSSFOUSBUJOH
range (62mA- 15A)
t 3P)4DPNQMJBOU
t )BMPHFOGSFFBWBJMBCMF
t 8JEFPQFSBUJOH
temperature range
t -PXUFNQFSBUVSF
rerating
© 2012 Littelfuse, Inc.
Specifications are subject to change without notice.
Axial Lead & Cartridge Fuses
251/253 Series
Please refer to www.littelfuse.com/series/251.html
or /253.html for current information.
PICO
®
ll > Very Fast-Acting > 251/253 Series
Ampere
Rating
(A)
Amp
Code
Ordering
Number
(Std.)
Ordering
Number
(Mil.)
Max
Voltage
Rating
(V)
Interrupting
Rating
Nominal
Cold
Resistance
(Ohms)
Nominal
Melting
I
2
t (A
2
sec)
Nom
Voltage
Drop
(V)
Agency Approvals
PS
E
TUV
QP
.062 .062 251.062 253.062 125
300 A @ rated
WPMUBHF%$
50 A @ rated
WPMUBHF"$
For CCC 7A:
70 A @ rated
WPMUBHF"$
For CCC 10A:
100 A @ rated
WPMUBHF"$
7.000 0.000113 1.4 x x x
.125 .125 251.125 253.125 125 1.700 0.00174 0.285 x x x
.250 .250 251.250 253.250 125 0.665 0.0116 0.24 x x x
.375 .375 251.375 253.375 125 0.395 0.0296 0.215 x x x
.500 .500 251.500 253.500 125 0.280 0.0598 0.2165 x x x x x
.630 .630 251.630 125 0.205 0.094 0.188 x x
.750 .750 251.750 253.750 125 0.175 0.153 0.176 x x x x
1.00 001. 251001. 253001. 125 0.128 0.256 0.194 x x x x x x
1.25 1.25 2511.25 125 0.100 0.390 0.2 x x x
1.50 01.5 25101.5 25301.5 125 0.0823 0.587 0.21 x x x x x
2.00 002. 251002. 253002. 125 0.0473 0.405 0.141 x x x x x x
2.50 02.5 25102.5 125 0.0360 0.721 0.132 x x x x x
3.00 003. 251003. 253003. 125 0.0290 1.19 0.131 x x x x x x
3.50 03.5 25103.5 125 0.0240 1.58 0.1205 x x x x
4.00 004. 251004. 253004. 125 0.0204 2.45 0.114 x x x x x x
5.00 005. 251005. 253005. 125 0.0155 4.14 0.11 x x x x x x
7.00 007. 251007. 253007. 125 0.0105 10.4 0.102 x x x x
10.0 010. 251010. 253010. 125 0.00705 25.5 0.1 x x x x
12.0 012. 251012. 32 0.0055 45.2 0.0878 x x
15.0 015. 251015. 253015. 32 0.00446 68.8 0.071 x x x
Electrical Specifications by Item
Note: )JHIFSBNQFSFSBUJOHTBSFBWBJMBCMF1MFBTFDPOUBDU-JUUFMGVTF5FDIOJDBM4VQQPSUPSZPVS-JUUFMGVTFQSPEVDUTSFQSFTFOUBUJWFGPSBTTJTUBODF
© 2012 Littelfuse, Inc.
Specifications are subject to change without notice.
Axial Lead & Cartridge Fuses
251/253 Series
Please refer to www.littelfuse.com/series/251.html
or /253.html for current information.
PICO
®
ll > Very Fast-Acting > 251/253 Series
251/253 Series
Average Time Current Curves
Soldering Parameters
100
10
1
0.1
0.01
0.001
.062A
0.05 0.1 1 10 100 1000
.125A
.250A
.375A
.500A
.750A
.630A
1A
1.5A
2A
2.5A
3A
3.5A
4A
5A
7A
10A
12A
15A
TIME IN SECONDS
CURRENT IN AMPERES
1.25A
Wave Parameter Lead-Free Recommendation
Preheat:
%FQFOETPO'MVY"DUJWBUJPO5FNQFSBUVSF
5ZQJDBM*OEVTUSZ3FDPNNFOEBUJPO
Temperature Minimum:
100
° C
Temperature Maximum:
150
° C
Preheat Time: 60-180 seconds
Solder Pot Temperature:
260
° C Maximum
Solder Dwell Time: 2-5 seconds
Recommended Hand Soldering Parameters:
4PMEFS*SPO5FNQFSBUVSF¡$¡$
Heating Time: 5 seconds max.
Note: These devices are not recommended for IR or
Convection Reflow process
Recommended Process Parameters:
Note:
1. Rerating depicted in this curve is in addition to the standard rerating of 25% for
continuous operation.
Temperature Rerating Curve
