SMM Datasheet, PDF (1/2 Pages) Bel Fuse Inc. – Square Ceramic Surface Mount Medium Blow Fuse

SMMD Sept.,2010
Type SMM
Square Ceramic Surface Mount Medium Blow Fuse
3812 Size
RoHS6 Compliant
Pb
Catalog Ampere Typical Cold Volt-drop Melting I²t
Number Rating Resistance @100% In @10In
(ohm) (Volt) max. (A²Sec) min.
SMM 20 20A
0.0025
0.09
270
Maximum
Power
Dissipation
(W)
1.8
SMM 25 25A
0.0019
0.08
420
2.0
SMM 30 30A
0.0013
0.07
1000
2.1
Consult manufacturer for other ratings
Electrical Characteristics
Testing Current
100%
200%
Blow Time
Minimum
Maximum
4 hrs
N/A
N/A
60 sec
Approvals
Safety Agency Approvals
Amp range / I.R. ability @ Volt
Recognized File No. E20624
20A - 30A / 100A@ 250V AC resistive
150A@125V AC resistive
300A@ 65V DC resistive
Physical Specification
Soldering Guidelines
Reflow Conditions Recommended: 240°C, 30 sec. max.
Pb-Free Process Compatibility:
When soldered to test boards using IR reflow in accordance with JEDEC
J-STD-020 (260°C, 40 sec. max.), SMM samples exhibited DCR change of
+10% to -20% from initial values.
Subsequent tests showed all samples complied with the stated electrical
characteristics on this data sheet.
NOT Recommended for Wave solder / Direct immersion / Hand Solder
Environmental Specification
Shock Resistance
MIL-STD-202G, Method 213B, Test Condition I (100 G's peak for 6 milliseconds).
Materials
Ceramic Body / Matte Tin Plated Brass Caps
Marking
On fuse:
"bel", "Current Rating" in black
'On label:
"bel", "SMM", Current Rating, Voltage Rating, Interrupting Rating,
Safety Logo and "
","
"(China RoHS compliant)
Packaging
2,000 fuses in 13 inches dia. reel, 16mm wide tape, 8mm pitch, per EIA Standard
481
Mechanical Dimensions
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).
Thermal Shock Resistance
MIL-STD-202G, Method 107G, Test Condition B (-65°C to +125°C)
Insulation Resistance:
MIL-STD-202G, Method 302, Test Condition A
(After Opening) 10,000 ohms minimum
Solderability:
MIL-STD-202G, Method 208H
Soldering Heat Resistance:
MIL-STD-202G, Method 210F
Operating Temperature
-55°C to +85°C Max.
3.1±0.1mm
(0.12''±0.004'')
3.1±0.1mm
(0.12''±0.004'')
3.8mm
(0.15")
2.0±0.2mm
(0.08''±0.008'')
9.8±0.2mm
(0.39''±0.008'')
5.6mm
(0.22")
4.1mm
(0.16")
NOTES:
– TEST CONDITIONS
For all SMM data, as well as UL Component investigation, all tests were conducted with fuse samples soldered on a PCB (1.6mm thick) test
board with copper traces measuring 0.1 mm nominal thickness (3 oz.clad), 10mm wide and 100 mm 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 ^oC in a 21 ^oC ambient (79 ^oC 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 SMM30 rating was 69 C (48 C 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 operation at currents
in this range may result in overheating of the fuse and/or desoldering of the fuse caps from the PCB pad.