Surface Mount Fuses
NANO
2®
> Slo-Blo
®
> 449 Series
449 Series Fuse
Description
PS
E
The lead free NANO
2
Slo-Blo
®
fuse is RoHS compliant
and 100% lead-free. This product is fully compatible with
lead-free solder alloys and higher temperature profiles
associated with lead-free assembly. The Slo-Blo
®
design
has enhanced inrush withstand characteristics over the
NANO
2
Fast-Acting Fuse. The unique time delay feature
of this fuse design helps solve the problem of nuisance
“opening” by accommodating inrush currents that normally
cause a fast-acting fuse to open.
Features
Agency Approvals
AGENCY
AGENCY FILE NUMBER
E10480
PS
E
®
temperature range
de-rating
AMPERE RANGE
375mA - 5A
1A - 5A
ratings available
Applications
Secondary protection for space constrained applications:
NBK030205
Electrical Characteristics for Series
% of Ampere
Rating
100%
200%
300%
800%
Opening Time
4 hours, Minimum
1 sec., Min.; 60 sec., Max.
0.2 sec., Min.; 3 sec., Max
0.02 sec., Min.; 0.1 sec., Max.
equipment
protection
Electrical Specifications by Item
Ampere
Rating
(A)
0.375
0.500
0.750
1.00
1.50
2.00
2.50
3.00
3.50
4.00
5.00
Max
Voltage
Rating
(V)
125
125
125
125
125
125
125
125
125
125
125
PSE: 100 amperes
@100 VAC
50 amperes @125 VAC/
VDC
Interrupting
Rating
Nominal Cold
Resistance
(Ohms)
1.5130
0.7633
0.4080
0.2516
0.1186
0.0708
0.0400
0.0352
0.0261
0.0227
0.0171
Nominal
Melting
2
I t (A
2
sec)
0.088
0.258
0.847
1.76
4.70
6.76
13.18
19.55
32.70
40.80
59.59
Agency Approvals
PS
E
Amp Code
0.375
0.500
0.750
001.
01.5
002.
02.5
003.
03.5
004.
005.
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Notes: - l
2
t calculated at 8ms. Resistance is measured at 10% of rated current, 25ºC
© 2009 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/449.html for current information.
53
Revised: January 7, 2009
449 Series
449 Series
Surface Mount Fuses
Introduction to Circuit Protection
Transientology
NANO
2®
> Slo-Blo
®
> 449 Series
Temperature Rerating Curve
Average Time Current Curves
.375A
.500A
1000
100
TIME IN SECONDS
10
1
Note:
1. Derating depicted in this curve is in addition to the standard derating of 25% for
continuous operation.
0.1
0.01
0
1
10
100
CURRENT IN AMPERES
Soldering Parameters
Reflow Condition
- Temperature Min (T
s(min)
)
Pre Heat
- Temperature Max (T
s(max)
)
- Time (Min to Max) (t
s
)
Average ramp up rate (Liquidus Temp
(T
L
) to peak
T
S(max)
to T
L
- Ramp-up Rate
Reflow
- Temperature (T
L
) (Liquidus)
- Temperature (t
L
)
Pb – Free assembly
150°C
60 – 120 secs
3°C/second max.
3°C/second max.
217°C
60 – 90 seconds
250
+0/-5
.750A
1A
1.5A
2A
2.5A
3A
3.5A
4A
5A
T
P
Ramp-up
t
P
Critical Zone
T
L
to T
P
Temperature
200°C
T
L
T
S(max)
Preheat
t
L
Ramp-down
T
S(min)
t
S
25
time to peak temperature
(t 25ºC to peak)
Time
Peak Temperature (T
P
)
Time within 5°C of actual peak
Temperature (t
p
)
Ramp-down Rate
Time 25°C to peak Temperature (T
P
)
Do not exceed
Wave Soldering Parameters
°C
20 – 40 seconds
5°C/second max.
8 minutes max.
260°C
260°C Peak
Temperature,
3 seconds max.
449 Series
54
Revised: January 7, 2009
© 2009 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/449.html for current information.
Surface Mount Fuses
NANO
2®
> Slo-Blo
®
> 449 Series
Product Characteristics
Materials
Product Marking
Operating
Temperature
Moisture
Sensitivity Level
Solderability
Insulation
Resistance (after
Opening)
Body:
Ceramic
Terminations:
Gold-plated Caps
Brand, Amperage Rating
-55°C to 125°C
Level 1, J-STD-020C
Vibration
MIL-STD-202, Method 208
MIL-STD-202, Method 302, Test Condition
A (10,000 ohms minimum)
Moisture Resistance
Salt Spray
Resistance to Soldering
Heat
Mechanical Shock
Thermal Shock
MIL
-STD-202, Method 107 Test
,
Condition B, 5 cycles, -65°C to
125°C, 15 minutes @ each extreme
MIL
-STD-202, Method 213, Test I:
Deenergized. 100G’s pk amplitude,
sawtooth wave 6ms duration, 3
cycles XYZ+xyz = 18 shocks
MIL
-STD-202, Method 201: 0.03"
amplitude, 10-55 Hz in 1 min. 2hrs
each XYZ=6hrs
MIL
-STD-202, Method 106, 10 cycles
Dimensions
6.86
(.270")
3.15
(.124")
2.95
(.116")
1.45
(.057")
6.10
(.240")
F
Part Numbering System
0449 001. M R
SERIES
AMP Code*
Refer to Electrical charac-
teristics table
QUANTITY Code
M = 1000 pcs
2.69
(.106")
T
1A
2.69
(.106")
1.96
(.077")
Recommended pad layout
PACKAGING Code
R = Tape and Reel
*Example:
0.375 Amp product is 0449.375MR
(1 amp product shown above).
Packaging
Packaging Option
12mm Tape and Reel
Packaging Specification
EIA RS-481-2 (IEC 286, part 3)
Quantity
1000
Quantity &
Packaging Code
MR
© 2009 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/449.html for current information.
55
Revised: January 7, 2009
449 Series
449 Series
MIL
-STD-202, Method 101, Test
Condition B (48hrs)
MIL
-STD-202, Method 210, Test
condition B (10 sec at 260°C)