Littelfuse 437 Series User Manual
Surface mount fuses, Ceramic fuse > 437 series
© 2013 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 12/19/13
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
AmpeRe RANge
e10480
0.250A ~ 8A
lR29862
0.250A ~ 8A
Features
Electrical Characteristics for Series
• Operating Temperature
from -55ºC to +150ºC
• 100% Lead-free and
RoHS compliant
• Suitable for both leaded
and lead-free reflow /
wave soldering
% of Ampere
Rating
Ampere Rating
Opening Time at 25ºC
100%
250mA - 8A
4 hours, Minimum
250%
750mA - 8A
5 seconds, Maximum
350%
250mA -500mA
5 seconds, Maximum
350%
750mA - 8A
1 second, Maximum
Applications
Ampere
Rating
(A)
Amp
Code
max.
Voltage
Rating (V)
Interrupting Rating
Nominal
Resistance
(Ohms)
2
Nominal
melting I
2
t
(A
2
Sec.)
3
Nominal Voltage
Drop At Rated
Current (V)
4
Nominal power
Dissipation At
Rated Current (W)
Agency Approvals
250mA
.250
125
50 A @ 125 V AC/DC
2.290
0.003
0.78
0.195
x
x
375mA
.375
125
1.330
0.010
0.60
0.225
x
x
500mA .500
63
50 A @ 63 V AC/DC
0.908
0.018
0.52
0.260
x
x
750mA
.750
63
0.665
0.064
0.45
0.335
x
x
1A
001.
63
0.360
0.100
0.41
0.415
x
x
1.25A
1.25
63
0.318
0.256
0.40
0.496
x
x
1.5A
01.5
63
0.209
0.324
0.39
0.579
x
x
1.75A
1.75
63
0.0703
0.075
0.27
0.474
x
x
2A
002.
63
0.058
0.144
0.17
0.345
x
x
2.5A
02.5
32
50 A @ 32 V AC/35 V DC
0.043
0.225
0.14
0.363
x
x
3A
003.
32
0.033
0.400
0.15
0.462
x
x
3.5A
03.5
32
0.027
0.576
0.16
0.560
x
x
4A
004.
32
0.022
1.024
0.16
0.618
x
x
5A
005.
32
0.016
1.936
0.09
0.484
x
x
7A
007.
32
0.010
4.900
0.11
0.760
x
x
8A
008.
32
0.0084
6.400
0.067
0.539
x
x
Electrical Specifications by Item
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.
• LCD Displays
• Servers
• Printers
• Scanners
• Data Modems
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.
Additional Information