Surface Mount Fuses
Ceramic Fuse > 437 Series
RoHS Pb
437 Series – 1206 Fast-Acting Fuse
Description
This 100% Lead-free, RoHS compliant and Halogen-free
fuse series has been designed specifically to provide over
current protection to circuits might encounter high working
ambient temperatures (up to 150ºC).
The general design ensures excellent temperature stability
and performance reliability.
In addition to this, the high I²t values typical of the
Littelfuse Ceramic Fuse family ensure high inrush current
withstand capability.
Features
• OperatingTemperature
from -55ºC to +150ºC
• Suitable for both leaded
and lead-free reflow /
wave soldering
Agency Approvals
• 100% Lead-free, Halogen-
Free and RoHS compliant • UL Recognized to UL/
CSA/NMX 248-1 and UL/
Agency
Agency File Number
Ampere Range
E10480
29862
0.250A - 8A
0.250A - 8A
CSA/NMX 248-14
Applications
• LCD Displays
• Servers
• Scanners
• Data Modems
• Printers
Electrical Characteristics for Series
% of Ampere
Ampere Rating
Rating
Additional Information
OpeningTime at 25ºC
100%
250%
350%
350%
250mA - 8A
750mA - 8A
4 hours, Minimum
5 seconds, Maximum
5 seconds, Maximum
1 second, Maximum
250mA -500mA
750mA - 8A
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Electrical Specifications by Item
Agency Approvals
Ampere
Rating
(A)
Max.
Voltage
Rating (V)
Nominal
Nominal
NominalVoltage
Drop At Rated
Current (V)4
Nominal Power
Dissipation At Rated
Current (W)
Amp
Code
Interrupting Rating1
Resistance Melting I2t
(Ohms)2
(A2Sec.)3
0.25
0.375
0.5
0.75
1.0
1.25
1.5
1.75
2.0
2.5
3.0
3.5
4.0
.250
.375
.500
.750
001.
1.25
01.5
1.75
002.
02.5
003.
03.5
004.
005.
0 0 7.
008.
125
125
63
63
63
63
63
63
63
45
45
45
45
45
32
32
2.29
1.33
0.908
0.665
0.42
0.318
0.209
0.071
0.058
0.043
0.033
0.027
0.022
0.0159
0.01
0.003
0.01
0.018
0.064
0.1
0.256
0.324
0.075
0.225
0.441
0.506
0.777
1.024
2.3
0.78
0.6
0.52
0.45
0.41
0.4
0.39
0.27
0.2
0.15
0.14
0.13
0.13
0.13
0.13
0.13
0.195
0.225
0.26
0.338
0.41
0.5
0.585
0.473
0.4
0.375
0.42
0.455
0.52
0.65
0.91
1.04
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
50 A @ 125 V AC/DC
50 A @ 63 V AC/DC
50A @ 45V AC/63V DC
50 A @ 32 V AC/35 V DC
5.0
7. 0
8.0
5.02
7.23
0.008
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. Contact Littelfuse if application transient surges are less than 1 ms.
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 Re-rating Curve”for additional re-rating information.
Devices designed to be mounted with marking code facing up.
© 2020 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: GD. 10/19/20