Surface Mount Fuses
Ceramic Fuse > 437 Series
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 that see 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
Agency Approvals
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AGENCY
AGENCY FILE NUMBER
AMPERE RANGE
0.250A ~ 8A
from -55ºC to +150ºC
and lead-free reflow /
wave soldering
E10480
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RoHS compliant
LR29862
0.250A ~ 8A
Applications
Electrical Characteristics for Series
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% of Ampere
Ampere Rating
OpeningTime at 25ºC
Rating
100%
250%
350%
350%
250mA - 8A
750mA - 8A
4 hours, Minimum
5 seconds, Maximum
5 seconds, Maximum
1 second, Maximum
250mA -500mA
750mA - 8A
Electrical Specifications by Item
Agency Approvals
Ampere
Rating
(A)
Max.
Voltage
Rating (V)
Nominal
Nominal Nominal Voltage Nominal Power
Amp
Code
Interrupting Rating
Resistance Melting I2t
Drop At Rated
Dissipation At
(Ohms)2
(A2Sec.)3
Current (V)4
Rated Current (W)
250mA .250
375mA .375
500mA .500
750mA .750
125
125
63
63
63
63
63
63
63
32
32
32
32
32
32
32
2.290
1.330
0.908
0.665
0.360
0.318
0.209
0.0703
0.058
0.043
0.033
0.027
0.022
0.016
0.010
0.0084
0.003
0.010
0.018
0.064
0.100
0.256
0.324
0.075
0.144
0.225
0.400
0.576
1.024
1.936
4.900
6.400
0.78
0.60
0.52
0.45
0.41
0.40
0.39
0.27
0.17
0.14
0.15
0.16
0.16
0.09
0.11
0.067
0.195
0.225
0.260
0.335
0.415
0.496
0.579
0.474
0.345
0.363
0.462
0.560
0.618
0.484
0.760
0.539
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
1A
1.25A
1.5A
1.75A
2A
001.
1.25
01.5
1.75
002.
02.5
003.
03.5
004.
005.
007.
008.
50 A @ 63 V AC/DC
2.5A
3A
3.5A
4A
50 A @ 32 V AC/DC
5A
7A
8A
Notes:
1. AC Interrupting Rating tested at rated voltage with unity power factor. DC Interrupting
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.
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 msecs. opening time.
Devices designed to be mounted with marking code facing up.
4. Nominal Voltage Drop measured at rated current after temperature has stabilized.
© 2009 Littelfuse, Inc.
437 Series
17
Revised: August 3, 2009
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/437.html for current information.