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.
Agency Approvals
AGENCY
AGENCY FILE NUMBER
E10480
LR29862
AMPERE RANGE
0.250A ~ 8A
0.250A ~ 8A
Features
from -55ºC to +150ºC
RoHS compliant
Applications
and lead-free reflow /
wave soldering
Electrical Characteristics for Series
% of Ampere
Rating
100%
250%
350%
350%
Ampere Rating
250mA - 8A
750mA - 8A
250mA -500mA
750mA - 8A
Opening Time at 25ºC
4 hours, Minimum
5 seconds, Maximum
5 seconds, Maximum
1 second, Maximum
Electrical Specifications by Item
Ampere
Max.
Amp
Rating
Voltage
Code
(A)
Rating (V)
250mA
375mA
500mA
750mA
1A
1.25A
1.5A
1.75A
2A
2.5A
3A
3.5A
4A
5A
7A
8A
.250
.375
.500
.750
001.
1.25
01.5
1.75
002.
02.5
003.
03.5
004.
005.
007
.
008.
125
125
63
63
63
63
63
63
63
32
32
32
32
32
32
32
Interrupting Rating
50 A @ 125 V AC/DC
Nominal Nominal Voltage Nominal Power Agency Approvals
Nominal
Drop At Rated
Dissipation At
Resistance Melting I
2
t
(A
2
Sec.)
3
Current (V)
4
Rated Current (W)
(Ohms)
2
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 @ 63 V AC/DC
50 A @ 32 V AC/DC
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 msecs. opening time.
4. Nominal Voltage Drop measured at rated current after temperature has stabilized.
© 2009 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/437.html for current information.
17
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.
437 Series
Revised: August 3, 2009
437 Series
LITTELFUSE [ LITTELFUSE ]
