Surface Mount Fuses Datasheet
438 Series
0603 Fast-Acting Fuse
RoHS Pb
Description
The 438 Series is a 100% Lead-free, RoHS compliant and
Halogen-free fuse series designed specifically to provide over-
current protection to circuits that operate under high working
ambient temperature up to 150ºC.
The general design ensures excellent temperature stability and
performance reliability.
The high I²t values which is typical in the Littelfuse Ceramic Fuse
family ensure high inrush current withstand capability.
Features & Benefits
■ OperatingTemperature from
■ Conforms to EN 60127-1 and
-55ºC to +150ºC
EN 60127-7
■ 100% Lead-free, RoHS
compliant and Halogen-free
■ CE Mark indicates suitability
for the European Market
■ Suitable for both leaded
and lead-free reflow / wave
soldering
■ UKCA Mark indicates suitability
for the UK Market
Additional Information
■ Recognized to UL/CSA/NMX
248-1 and UL/CSA/NMX 248-
14
Applications
■ Handheld Electronics
■ LCD Displays
Resources
Accessories
Samples
■ Hard Disk Drives
■ SD Memory Cards
Agency Approvals
■ Battery Packs
Agency
Agency File Number
Ampere Range
E10480
29862
J50489122
N/A
0.250A – 6A
0.250A – 6A
0.250A - 6A
0.250A - 6A
0.250A - 6A
Electrical Characteristics for Series
% of Ampere Rating
Ampere Rating
OpeningTime at 25ºC
100%
250%
0.25A – 6A
0.25A – 6A
4 Hours, Minimum
N/A
5 Seconds, Maximum
Electrical Specifications by Item
Ampere
Rating
(A)
Nominal
Nominal NominalVoltage Nominal Power
Agency Approvals
Amp Max.Voltage
Code Rating (V)
Interrupting Rating
Resistance Melting I2t Drop At Rated
Dissipation At
(Ohms)2
2.218
1.247
0.829
0.466
0.310
0.200
0.174
0.1405
0.051
0.0324
0.0255
0.0205
0.0170
0.0115
(A2Sec.)3
0.0017
0.0041
0.0100
0.0281
0.0593
0.0510
0.0902
0.1440
0.1490
0.1977
0.2922
0.4752
0.6920
0.7398
1.3838
Current (V)4
0.550
0.488
0.486
0.378
0.351
0.365
0.368
0.360
0.107
0.095
0.093
0.082
0.079
0.074
Rated Current (W)
0.250 .250
0.375 .375
0.500 .500
0.750 .750
1.00
1.25
1.50
1.75
2.00 002.
2.50 02.5
3.00 003.
3.50 03.5
4.00 004.
5.00 005.
6.00 006.
63VDC
63VDC
63VDC
63VDC
63VDC
63VDC
63VDC
63VDC
32
0.138
0.183
0.243
0.284
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
50A @ 63VDC
50A @ 32VAC
001.
1.25
01.5
1.75
0.351
0.456
0.552
0.540
0.214
0.238
0.279
0.287
0.316
0.370
32
32
32
32
32
24
50A @ 32VDC/12VAC
50A @ 24VDC/12VAC 0.0085
0.072
0.432
Notes:
Devices designed to carry rated current for 4 hours minimum. It is recommended that devices be operated
continuously at no more than 80% rated current. See “Temperature Re-rating Curve”for additional re-rating
information.
1. AC Interrupting Rating tested at rated voltage with unity power factor. DC Interrupting Rating tested at rated
voltage with time constant < 0.8 msec.
2. Nominal Resistance measured with < 10% rated current.
3. Nominal Melting I²t measured at 1 msec. opening time.
Devices designed to be mounted with marking code facing up.
4. Nominal Voltage Drop measured at rated current after temperature has stabilized.
© 2023 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: GD. 08/11/23
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