Axial Lead & Cartridge Fuses
PICO® ll > Very Fast-Acting > 251/253 Series
251/253 Series,
PS
E
PICO® II, Very Fast-Acting Fuse
TUV QPL
Description
The PICO® II Very Fast-Acting Fuse is designed to meet an
extensive array of performance characteristics in a
space-saving subminiature package.
Features
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t 4NBMMTJ[F
t 8JEFDVSSFOUSBUJOH
range (62mA- 15A)
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t 8JEFPQFSBUJOH
temperature range
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rerating
Applications
Agency Approvals
4FDPOEBSZQSPUFDUJPOGPSTQBDFDPOTUSBJOFEBQQMJDBUJPOT
Agency File Number
Ampere Range
E10480
62mA - 15A
LR 29862
62mA - 15A
PS
E
JET 1896-31007-1001
1A - 5A
TUV
J50158379
500mA - 10A
QPL
FM10
62mA - 15A
2009010207366577 –
500mA to 5A
Pending – 7A, 10A
500mA, 1A, 2A, 2.5A,
3A, 4A, 5A, 7A, 10A
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t 1PXFSTVQQMZ
t -$%NPOJUPS
t "VEJP7JEFPTZTUFN
t -$%CBDLMJHIUJOWFSUFS
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Electrical Characteristics for Series
% of Ampere
Rating
Ampere Rating
100%
62mA - 15A
4 Hours, Min.
62mA - 7A
1 Second, Max.
200%
275%
400%
1000%
© 2009 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/251.html
or /253.html for current information.
199
Revised: February 8, 2010
Opening Time
10A
3 Seconds, Max.
12 - 15A
10 Seconds, Max.
500mA, 1A, 2A,
2.5A, 3A, 4A, 5A,
7A, 10A
500mA, 1A, 2A,
2.5A, 3A, 4A, 5A,
7A, 10A
500mA, 1A, 2A,
2.5A, 3A, 4A, 5A,
7A, 10A
300 msecs., Max.
30 msecs., Max.
4 msecs., Max.
251/253 Series
251/253 Series
Agency
Introduction
to &
Circuit
Protection
Axial Lead
Cartridge
Fuses
Transientology
PICO® ll > Very Fast-Acting > 251/253
Series
Electrical Specifications by Item
Agency Approvals
Nom
Max
Nominal
Ampere
Nominal
Ordering Ordering
Voltage
Amp
Voltage Interrupting
Cold
Rating
Melting
Number Number
Drop
Code
Rating
Rating
Resistance 2
(A)
I t (A2 sec)
(Std.)
(Mil.)
(V)
(V)
(Ohms)
.062
.125
.250
.375
.500
.630
.750
1.00
1.25
1.50
2.00
2.50
3.00
3.50
4.00
5.00
7.00
10.0
12.0
15.0
.062
.125
.250
.375
.500
.630
.750
001.
1.25
01.5
002.
02.5
003.
03.5
004.
005.
007.
010.
012.
015.
251.062
251.125
251.250
251.375
251.500
251.630
251.750
251001.
2511.25
25101.5
251002.
25102.5
251003.
25103.5
251004.
251005.
251007.
251010.
251012.
251015.
253.062
253.125
253.250
253.375
253.500
253.750
253001.
25301.5
253002.
253003.
253004.
253005.
253007.
253010.
253015.
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
125
32
32
300 A @ rated
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50 A @ rated
WPMUBHF"$
For CCC 7A:
70 A @ rated
WPMUBHF"$
For CCC 10A:
100 A @ rated
WPMUBHF"$
7.000
1.700
0.665
0.395
0.280
0.205
0.175
0.128
0.100
0.0823
0.0473
0.0360
0.0290
0.0240
0.0204
0.0155
0.0105
0.00705
0.0055
0.00446
0.000113
0.00174
0.0116
0.0296
0.0598
0.094
0.153
0.256
0.390
0.587
0.405
0.721
1.19
1.58
2.45
4.14
10.4
25.5
45.2
68.8
1.4
0.285
0.24
0.215
0.2165
0.188
0.176
0.194
0.2
0.21
0.141
0.132
0.131
0.1205
0.114
0.11
0.102
0.1
0.0878
0.071
PS
E
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TUV QPL
x
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P
P
x
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P = Pending
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251/253 Series
200
© 2009 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/251.html
or /253.html for current information.
Axial Lead & Cartridge Fuses
PICO® ll > Very Fast-Acting > 251/253 Series
.250A
.375A
.500A
.630A
.750A
1A
1.25A
1.5A
2A
2.5A
3A
3.5A
4A
5A
7A
10A
12A
15A
.125A
Average Time Current Curves
.062A
Temperature Rerating Curve
100
TIME IN SECONDS
10
1
0.1
Note:
1. Rerating depicted in this curve is in addition to the standard rerating of 25% for
continuous operation.
0.01
Soldering Parameters
0.001
0.05 0.1
Recommended Process Parameters:
Wave Parameter
1
10
100
1000
CURRENT IN AMPERES
Lead-Free Recommendation
Preheat:
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Temperature Minimum:
100° C
Temperature Maximum:
Preheat Time:
150° C
60-180 seconds
Solder Pot Temperature:
260° C Maximum
Solder Dwell Time:
2-5 seconds
251/253 Series
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Recommended Hand-Solder Parameters:
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Heating Time: 5 seconds max.
Note: These devices are not recommended for IR or
Convection Reflow process.
© 2009 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/251.html
or /253.html for current information.
201
251/253 Series
Introduction
to &
Circuit
Protection
Axial Lead
Cartridge
Fuses
Transientology
PICO® ll > Very Fast-Acting > 251/253
Series
Product Characteristics
Materials
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Operating Temperature
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Solderability
.*-45%
.FUIPE
Shock
Lead Pull Force
.*-45%
.FUIPE
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.*-45%
.FUIPE
5FTU
Condition I (100 G’s peak for 6
msecs.)
Vibration
Fuses To MIL SPEC
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QPL for MIL-PRF-23419. To order, change
251 to 253
.*-45%
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)[
.FUIPE
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Moisture Resistance
.*-45%
.FUIPE
Resistance to Soldering
Heat
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and up to 260ºC, maximum
Flammability Rating
UL 94V–0
Part Numbering System
Dimensions
251 Series (RoHS Version) Markings
(T1 lead length)
62.7 (2.468")
52.4 (2.062")*
27.78
(1.094")
7.11 (.280")
1A
6.35 (.25")
tape
LF
5.0 (.197")
1A
0251 xxxx N R T1 L
27.78
(1.094")
2.80
(.11")
MAX
Series
251 = Standard type
253 = Military type
6.35 (.25")
tape
Current Rating
LF
Refer to Amp Code column of
Electrical Specifications Table
Wire Diameter:
0.64 (.025") for 0.62-10.0 amp,
0.81 (.032") for 12-15 amp
Quantity
251 Series (RoHS and Halogen-free Version) Markings
(T1 lead length)
62.7 (2.468")
52.4 (2.062")*
27.78
(1.094")
7.11 (.280")
LF
6.35 (.25")
tape
27.78
(1.094")
1A
Type of Packaging
2.80
(.11")
MAX
5.0 (.197")
1A
N = 5000
P = 2000
M = 1000
H = 100
R = Reel
A = Ammo Pack
X = Loose Pack
6.35 (.25")
tape
LF
Wire Diameter:
0.64 (.025") for 0.62-10.0 amp,
0.81 (.032") for 12-15 amp
Lead Length
The default lead length for Ammo pack and
Loose pack is now T1 for 251 series, and
remains T3 for 253 series, therefore:
T1 = 52.4mm (2.062”), 251 series only*
Blank = 52.4mm (2.062”) for 251 series*
or 73mm (2.874”) for 253 series**
253 Series (RoHS Version) Markings
(T3 lead length)
83.31 (3.28")
38.1
(1.5")
6.35 (.25")
tape
73.0 (2.874")**
7.11 (.280")
LF
1A
LF
1A
38.1
(1.5")
2.61 (.103")
MAX
5.0 (.197")
Option Codes
6.35 (.25")
tape
L = RoHS
HF = RoHS and Halogen-free
(for 251 Series only)
Wire Diameter:
0.64 (.025") for 0.62-10.0 amp,
0.81 (.032") for 15 amp
Packaging
Packaging Option
5NN
5BQFBOE3FFM
5NN h
5BQFBOE3FFM
Packaging Specification
Quantity &
Packaging Code
EIA 296
1MFBTFSFGFSUPBWBJMBCMFRVBOUJUJFT
BCPWFJO1BSU/VNCFSJOH4ZTUFNw
EIA 296
5IFEFGBVMUMFBEMFOHUIGPSCPUIBNNPQBDLBOEMPPTFQBDLJT5GPSBOEJT5GPS
/PUFT
5EJNFOTJPOJTEFåOFEBTUIFMFOHUIPGUIFDPNQPOFOUCFUXFFOUIFUXPUBQFT5IFGVMMDPNQPOFOUMFOHUIJTNN
T1 length is for 251 series only.
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T3 length is for 253 series only.
251/253 Series
202
© 2009 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/251.html
or /253.html for current information.
