Data Sheet

Type
SMM
2
/
4
Bel Fuse Inc.
206 Van Vorst Street
Jersey City, NJ 07302 USA
+1
201.432.0463
[e-mail]
belfuse.com/circuit
-
protection
© 201
8
Bel
Fuse, Inc.
Rev.
SMM
Nov
2018
Environmental Specifications
Electrical S
pecifications
Catalog
Number
Ampere
Rating
Nominal
Cold
Resistance
(ohms)
Nominal
Volt
-
drop
@100% In
(Volt)
max.
Voltage and
Interrupting
Ratings
Melting I²T
@10 In
(A²
Sec)
Min.
Nominal
Power
Dissipation
(W)
Agency
Approvals
SMM 10
10A
0.0056
0.18
See Table of Safety
Approvals on Page 1
for Voltage and
associated
Interrupting Ratings
50
1.8
Y
SMM
15
15A
0.0036
0.12
110
1.8
Y
SMM 20
20A
0.0025
0.09
270
1.8
Y
SMM 25
25A
0.0019
0.08
420
2.0
Y
SMM
30
30A
0.0013
0.07
1000
2.1
Y
Consult manufacturer for other ratings
Soldering Guidelines
Reflow Conditions Recommended
240
℃
, 30 sec. max.
When
soldered to test boards using IR reflow in accordance with above 240
℃
, SMM samples exhibited DCR change of + 10% to
-
20% from initial values, the fuse may emit solder.
Subsequent tests showed all samples complied with the stated electrical characteristics
on this data sheet.
NOTES:
Test Conditions
For all SMM data, as well as UL Component investigation , all tests were conducted wi
t
h fuse samples soldered on a PCB (1.6mm
thick) test board with copper traces measuring 0.1mm nominal thickness (3 oz. clad), 1
0mm wide and 100mm overall length.
-
UL Condition of Acceptability
-
the following information is contained in the UL Component Recognition for SMM Fuse Series:
The maximum temperature recorded in open air was 100
℃
in a 21
℃
ambient (79
℃
rise). Consideration should be given to checking
operating temperatures in end
-
use application with regard to thermal index of surrounding materials and components.
(Maximum temperature recorded at 80% of rating (24A) for the SMM
30 rating was 69
℃
(48
℃
rise).
Caution:
-
Minimum fusing point:
The SMM Series fuses are NOT intended to be operated at currents between 100% and 200% of ampere rating.
Prolonged
0
peration at currents in this range may result in overheating of the fuse and/or desoldering of the fuse
caps from the PCB pad
.
Shock Resistance
MIL
-
STD
-
202G,
Method 213B, Test Condition 1
(100 G's peak for 6 milliseconds; Sawtooth waveform)
Vibration Resistance
MIL
-
STD
-
202G, Method 201A
(10
-
55 Hz,
0.06 inch, total excursion).
Salt Spray Resistance
MIL
-
STD
-
202G, Method 101E, Test Condition B
(48 hrs).
Insulation Resistance
MIL
-
STD
-
202G, Method 302, Test Condition A
(After Opening) 10,000 ohms minimum.
Solderability
MIL
-
STD
-
202G, Method 208H
Resistance to solder Heat
MIL
-
STD
-
202G, Method 210F
Thermal Shock
MIL
-
STD
-
202G, Met
hod 107G, Test Condition B
(
-
65
℃
to +125
℃
).
Operating Temperature
-
55
℃
to +125
℃
Moisture Sensitivity Level
1 ( Peak Temperature at 240
℃
for 30 seconds max )
Spe
cifications subject to change without notice