Cartridge and Axial Axial FusesFuses
Cartridge and Lead Lead
PICO
®
II > Very Fast-Acting > 251/253 251/253 Series
PICO
®
II > Very Fast-Acting > Series
RoHS
251/253 Series,
PICO
®
II, Very Fast-Acting Fuse
®
®
PS
E
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
temperature range
(62mA- 15A)
Applications
Agency Approvals
Agency
®
Agency File Number
Ampere Range
E10480
®
62mA - 15A
62mA - 15A
1A - 5A
500mA - 10A
62mA - 15A
LR 29862
JET 1896-31007-1001
J02037794
FM10
Electrical Characteristics
% of Ampere
Rating
100%
200%
Ampere Rating
1/16–15
1/16–7
10
12-15
Opening Time
Min.
Max.
Max.
Max.
PS
E
TUV
QPL
Electrical Characteristics
Max
Nominal
Ampere
Ordering Ordering
Nominal
Amp
Voltage Interrupting
Cold
Rating
Number Number
Melting
Code
Rating
Rating
Resistance
2
(A)
(Std.)
(Mil.)
I t (A
2
sec)
(V)
(Ohms)
.062
.125
.250
.375
.500
.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
Note:
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com for current information.
1
Revised: August 14, 2008
251/253 Series
Nom
Voltage
Drop
(mV)
1.4
0.285
0.24
0.215
0.2165
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
Agency Approvals
®
®
PS
E
TUV
QPL
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
.062
.125
.250
.375
.500
.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
251.750
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
32
32
300 amperes
at rated
50 amperes at
VAC
7
.000
1.700
0.665
0.395
0.280
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
0.153
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
x
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x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
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x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
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x
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x
x
Cartridge and Axial Lead Fuses
PICO
®
II > Very Fast-Acting > 251/253 Series
Temperature Rerating Curve
Average Time Current Curves
0.062A
0.125A
0.250A
0.375A
0.50A
0.75A
1.00A
1.25A
1.50A
2.0A
2.5A
3.0A
3.5A
4A
5A
7A
10A
12A
15A
1
10
100
CURRENT IN AMPERES
100
10
TIME IN SECONDS
1
0.1
Soldering Parameters
Recommended Process Parameters:
Wave Parameter
Preheat:
Temperature Minimum:
Temperature Maximum:
Preheat Time:
Solder Pot Temperature:
Solder Dwell Time:
100
°
C
150
°
C
60-180 seconds
260
°
C Maximum
2-5 seconds
Lead-Free Recommendation
0.01
0.001
0.05 0.1
1000
Recommended Hand-Solder Parameters:
Note: These devices are not recommended for IR or
Convection Reflow process.
251/253 Series
2
Revised: August 14, 2008
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com for current information.
Cartridge and Axial Axial FusesFuses
Cartridge and Lead Lead
PICO
®
II > Very Fast-Acting > 251/253 251/253 Series
PICO
®
II > Very Fast-Acting > Series
Product Characteristics
Materials
Solderability
Lead Pull Force
Vibration
Fuses To MIL SPEC
251 to 253
Moisture Resistance
Resistance to Soldering
Heat
Flammability Rating
O
Operating Temperature
Shock
Condition I (100 G’s peak for 6
C
and up to 260º
UL 94V–0
Dimensions
(T1 lead length)
62.7 (2.468")
52.4 (2.062")*
7.11 (.280")
Part Numbering System
251 series
0251 xxxx N R T1 L
27.78
(1.094")
27.78
(1.094")
Series
251
= Standard type
253
= Military type
1A
6.35 (.25")
tape
5.0 (.197")
F
L
Current Rating
2.80 (.11")
MAX
6.35 (.25")
tape
Refer to Amp Code column of
Electrical Characteristics Table
1A
F
L
Quantity
N
= 5000
P
= 2000
M
= 1000
H
= 100
V
=5
Wire Diameter:
0.64 (.025") for 0.62-10.0 amp,
0.81 (.032") for 12-15 amp
(T3 lead length)
83.31 (3.28")
38.1
(1.5")
73.0 (2.874")**
7.11 (.280")
38.1
(1.5")
253 series
Type of Packaging
R = Reel
A = Ammo Pack
X = Loose Pack
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**
F
L
6.35 (.25")
tape
5.0 (.197")
1A
2.80 (.11")
MAX
6.35 (.25")
tape
F
L
1A
Wire Diameter:
0.64 (.025") for 0.62-10.0 amp,
0.81 (.032") for 15 amp
RoHS
Packaging
Packaging Option
Packaging Specification
EIA 296
EIA 296
Quantity &
Packaging Code
T1 length is for 251 series only.
T3 length is for 253 series only.
©2008 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com for current information.
3
Revised: August 14, 2008
251/253 Series
