Littelfuse 494 Series User Manual
Surface mount fuses
© 2013 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 12/19/13
Surface Mount Fuses
Thin Film > 0603 Size > Fast-Acting > 494 Series
494 Series Fuse, NRA Special Series Integrated Circuit Protector
Description
Agency Approvals
AgeNCy
AgeNCy FIle NumbeR
AmpeRe RANge
®
e10480
250mA - 5A
lR29862
250mA - 5A
Electrical Characteristics for Series
Features
• Compatible with lead-
free solders and higher
temperature profiles
• High performance
materials provide
improved performance
in elevated ambient
temperature applications
• Marked on top surface
with code to allow ampere
rating identification
without testing
• Low profile for height
sensitive applications
• Flat top surface for pick-
and-place operations
• Element-covering material
is resistant to industry
standard cleaning
operations
• Mounting pad and
electrical performance are
identical to Littelfuse 431
and 434 Series products
• Alloy-based element
construction provides
superior inrush withstand
characteristics (I
2
t) over
ceramic or glass-based
0603 fuse products
% of Ampere
Rating
Opening Time at 25
O
C
100%
4 hours, Minimum
200%
5 sec., Maximum
300%
0.2 sec., Maximum
Applications
®
The 494 Series Fast-Acting SMF is an ultra small (0603
size) thin-film device designed for secondary protection
of circuits used in space constrained applications such
as hand-held portable electronic devices. This series is
100% lead-free and meets the requirements of the RoHS
directive. New Halide-Free 494 Series fuses are available
to order using the “HF” suffix. See Part Numbering section
for additional information.
• Cell phones
• Battery packs
• Digital cameras
• DVD players
• Hard disk
drives
Secondary protection for space constrained applications:
Ampere
Rating
(A)
Amp
Code
max
Voltage
Rating
(V)
Interrupting
Rating
Nominal Cold
Resistance
(Ohms)
Nominal
melting
I
2
t (A
2
sec)
Nom
Voltage
Drop
(mV)
Nom
power
Dissipation
(W)
Agency Approvals
®
0.250
.250
32
50A @32V AC/DC
0.5450
0.0030
158.56
0.0396
x
x
0.375
.375
32
0.2900
0.0053
128.03
0.0480
x
x
0.500
.500
32
0.1870
0.0087
115.71
0.0579
x
x
0.750
.750
32
0.1170
0.0171
107.33
0.0805
x
x
1.00
001.
32
0.0710
0.0212
89.10
0.0891
x
x
1.25
1.25
32
35A @32V AC/DC
0.0530
0.0518
84.32
0.1054
x
x
1.50
01.5
32
0.0410
0.0766
81.14
0.1217
x
x
1.75
1.75
32
0.0320
0.0903
78.75
0.1378
x
x
2.00
002.
32
0.0300
0.1103
78.22
0.1564
x
x
2.50
02.5
32
0.0220
0.1440
76.10
0.1903
x
x
3.00
003.
32
0.0180
0.2403
75.04
0.2251
x
x
3.50
03.5
32
0.0150
0.4306
74.25
0.2599
x
x
4.00
004.
32
0.0130
0.5760
73.72
0.2949
x
x
5.00
005.
32
0.0090
0.9000
72.71
0.3635
x
x
Electrical Specifications by Item
1. Measured at 10% of rated current, 25ºC. 2. Measured at rated voltage.
Additional Information