Surface Mount Fuses
Ceramic Fuse > 438 Series
438 Series – 0603 Fast-Acting Fuse
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.
Agency Approvals
AGENCY
AGENCY FILE NUMBER
E10480
LR29862
AMPERE RANGE
0.250A – 6A
0.250A – 6A
Features
• Operating Temperature
from -55ºC to +150ºC
• 100% Lead-free, RoHS
compliant and Halogen-
free
Applications
• Suitable for both leaded
and lead-free reflow /
wave soldering
Electrical Characteristics for Series
% of Ampere
Rating
100%
250%
Ampere Rating
0.250A – 6A
0.250A – 6A
Opening Time at 25ºC
4 Hours, Minimum
5 Seconds, Maximum
• Handheld Electronics
• LCD Displays
• Battery Packs
• Hard Disk Drives
• SD Memory Cards
• Automotive Electronics
Electrical Specifications by Item
Ampere
Max.
Amp
Rating
Voltage
Code
(A)
Rating (V)
0.25
0.375
0.5
0.75
1
1.25
1.5
1.75
2
2.5
3
3.5
4
5
6
Notes:
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.
4. Nominal Voltage Drop measured at rated current after temperature has stabilized.
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
Rerating Curve”for additional rerating information.
Devices designed to be mounted with marking code facing up.
Interrupting Rating
Nominal
Nominal Nominal Voltage Nominal Power Agency Approvals
Resistance Melting I
2
t
Drop At Rated
Dissipation At
(Ohms)
2
(A
2
Sec.)
3
Current (V)
4
Rated Current (W)
2.024
1.247
0.829
0.466
0.310
0.200
0.174
0.125
0.051
0.0324
0.0252
0.0203
0.0169
0.0113
0.0087
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
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
0.072
0.138
0.183
0.243
0.284
0.351
0.456
0.552
0.540
0.214
0.238
0.279
0.287
0.316
0.370
0.432
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
.250
.375
.500
.750
001.
1.25
01.5
1.75
002.
02.5
003.
03.5
004.
005.
006.
63
63
63
63
63
63
63
63
32
32
32
32
32
32
24
50A @ 63VDC
50A @ 32VAC
50A @ 32VDC/12VAC
50A @ 24VDC/12VAC
© 2009 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/438.html for current information.
1
Revised: February 15, 2012
438 Series
438 Series