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,
Halogen Free 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
Free
®
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: December 17, 2010
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
.750A
1A
1.5A
2A
2.5A
3A
3.5A
4A
5A
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
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
Temperature,
3 seconds max.
449 Series
54
© 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)
Moisture Resistance
A (10,000 ohms minimum)
Body:
Ceramic
Terminations:
Brand, Amperage Rating
-55°C to 125°C
Mechanical Shock
Thermal Shock
Condition B, 5 cycles, -65°C to
125°C, 15 minutes @ each extreme
sawtooth wave 6ms duration, 3
Vibration
Resistance to Soldering
Heat
condition B (10 sec at 260°C)
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
2.69
(.106")
T
1A
2.69
(.106")
1.96
(.077")
Recommended pad layout
PACKAGING Code
*Example:
0.375 Amp product is 0449.375MR
(1 amp product shown above).
Packaging
Packaging Option
12mm Tape and Reel
Packaging Specification
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
449 Series
449 Series
Salt Spray
Condition B (48hrs)
PCB设计
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