© 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
Materials
&ODBQTVMBUFE&QPYZ$PBUFE
Body:1VSF5JODPBUFE$PQQFSXJSFMFBET
Solderability .*-45%.FUIPE
Lead Pull Force
.*-45%.FUIPE5FTU$POEJUJPO
"XJMMXJUITUBOEBMCTBYJBMQVMMUFTU
Fuses To MIL SPEC
4FSJFTJTBWBJMBCMFJO'.PO
QPL for MIL-PRF-23419. To order, change
251 to 253
Product Characteristics
Operating Temperature o$UP$
Shock
.*-45%.FUIPE5FTU
Condition I (100 G’s peak for 6
msecs.)
Vibration
.*-45%.FUIPEo
)[.FUIPE5FTU$POEJUJPO$
o)[BU(T1FBL
Moisture Resistance .*-45%.FUIPE
Resistance to Soldering
Heat
8JUITUBOETTFDPOETBCPWF
O
C
and up to 260ºC, maximum
Flammability Rating UL 94V–0
Dimensions
Packaging
Part Numbering System
Packaging Option Packaging Specification
Quantity &
Packaging Code
5NN5BQFBOE3FFM EIA 296
1MFBTFSFG
FSUPBWBJMBCMFRVBOUJUJFT
above in "Part Numbering System”
5NNh5BQFBOE3FFM EIA 296
0251 xxxx N R T1 L
Lead Length
Type of Packaging
Quantity
Current Rating
Series
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**
R = Reel
A = Ammo Pack
X = Loose Pack
N = 5000
P = 2000
M = 1000
H = 100
Refer to Amp Code column of
Electrical Specifications Table
251
= Standard type
253
= Military type
Option Codes
L = RoHS + HF
5IFEFGBVMUMFBEMFOHUIGPSCPUIBNNPQBDLBOEMPPTFQBDLJT5GPSBOEJT5GPS
/PUFT 5EJNFOTJPOJTEFmOFEBTUIFMFOHUIPGUIFDPNQPOFOUCFUXFFOUIFUXPUBQFT5IFGVMMDPNQPOFOUMFOHUIJTNN T1 length is for 251 series only.
5EJNFOTJPOJTEFmOFEBTUIFMFOHUIPGUIFDPNQPOFOUCFUXFFOUIFUXPUBQFT5IFGVMMDPNQPOFOUMFOHUIJTNNwT3 length is for 253 series only.
Wire Diameter:
0.64 (.025") for 0.62-10.0 amp,
0.81 (.032") for 15 amp
Wire Diameter:
0.64 (.025") for 0.62-10.0 amp,
0.81 (.032") for 12-15 amp
2.61 (.103")
MAX
6.35 (.25")
tape
5.0 (.197")
6.35 (.25")
tape
38.1
(1.5")
38.1
(1.5")
7.11 (.280")
83.31 (3.28")
253 Series (RoHS Version) Markings
(T3 lead length)
L
1 A
L
1 A
73.0 (2.874")**
L
1 A
F
L
1 A
27.78
(1.094")
27.78
(1.094")
7.11 (.280")
62.7 (2.468")
52.4 (2.062")*
2.80
(.11")
MAX
6.35 (.25")
tape
5.0 (.197")
6.35 (.25")
tape
251 Series (RoHS and Halogen-free Version) Markings
(T1 lead length)
Wire Diameter:
0.64 (.025") for 0.62-10.0 amp,
0.81 (.032") for 12-15 amp
F
L
1 A
F
L
1 A
27.78
(1.094")
27.78
(1.094")
7.11 (.280")
62.7 (2.468")
52.4 (2.062")*
2.80
(.11")
MAX
6.35 (.25")
tape
5.0 (.197")
6.35 (.25")
tape
251 Series (RoHS Version) Markings
(T1 lead length)
F
F
F
