Surface Mount Fuses
NANO2® > Slo-Blo® Fuse > 449 Series
449 Series Fuse
RoHS Pb
PS
E
Description
The lead free NANO2® 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® fuse design has enhanced inrush withstand
characteristics over the NANO2® 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
PS
E
Agency File Number
Ampere Range
E10480
0.375A - 5A
NBK030205-E10480B
1A - 5A
Electrical Characteristics for Series
% of Ampere Rating
• Low temperature
rerating
• UL Recognized to UL/CSA/
NMX UL 248-1 and UL/
CSA/NMX UL 248-14
• Conforms to DENAN’s
Appendix 3
Applications
Opening Time
100%
4 hours, Minimum
200%
1 sec., Min.; 60 sec., Max.
300%
0.2 sec., Min.; 3 sec., Max
800%
0.002 sec., Min.; 0.1 sec., Max.
Additional Information
Datasheet
• Lead-free, Halogen free
and RoHS compliant
• Small size
• Wide range of current
ratings available
• Wide operating
temperature range
Secondary protection for space constrained applications:
• Storage system
• Notebook PC
• Telecom system
• LCD/PDP TV
• Wireless basestation
• LCD monitor
• White goods
• LCD/PDP panel
• Game console
• LCD backlight inverter
• Office Automation
• Portable DVD player
equipment
• Power supply
• Battery charging circuit
• Networking
protection
• PC server
• Industrial equipment
• Cooling fan system
Samples
Resources
Electrical Specifications by Item
Ampere Rating
(A)
Amp Code
Max
Voltage Rating
(V)
Interrupting
Rating
Nominal Cold
Resistance
(Ohms)
Nominal Melting
I2t (A2sec)
Agency Approvals
PS
E
0.375
.375
125
1.5130
0.088
x
0.500
.500
125
0.7633
0.258
x
0.750
.750
125
0.4080
0.847
x
1.00
001.
125
0.2516
1.76
x
1.50
01.5
125
0.1186
4.70
x
x
2.00
002.
125
0.0708
6.76
x
x
2.50
02.5
125
0.0400
13.18
x
x
3.00
003.
125
0.0352
19.55
x
x
3.50
03.5
125
0.0261
32.70
x
x
4.00
004.
125
0.0227
40.80
x
x
5.00
005.
125
0.0171
59.59
x
x
50A @125 VAC/VDC
PSE: 100A @100 VAC
x
Notes - l2t calculated at 8ms. Resistance is measured at 10% of rated current, 25ºC
© 2019 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 11/21/19
Surface Mount Fuses
NANO2® > Slo-Blo® Fuse > 449 Series
.750A
1A
1.5A
2A
2.5A
3A
3.5A
4A
5A
Average Time Current Curves
.375A
.500A
Temperature Re-rating Curve
1000
TIME IN SECONDS
100
10
1
Note:
1. Rerating 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
Pb – Free assembly
Pre Heat
- Temperature Min (Ts(min))
150°C
- Temperature Max (Ts(max))
200°C
- Time (Min to Max) (ts)
60 – 180 secs
Average ramp up rate (Liquidus Temp (TL) to peak
3°C/second max.
TS(max) to TL - Ramp-up Rate
3°C/second max.
Reflow
- Temperature (TL) (Liquidus)
217°C
- Temperature (tL)
60 – 150 seconds
Peak Temperature (TP)
260+0/–5 °C
Time within 5°C of actual peak Temperature (tp)
20 – 40 seconds
Ramp-down Rate
5°C/second max.
Time 25°C to peak Temperature (TP)
8 minutes max.
Do not exceed
260°C
Wave Soldering Parameters
tP
TP
Critical Zone
TL to TP
Ramp-up
TL
TS(max)
Temperature
Reflow Condition
tL
Ramp-down
TS(min)
25
Preheat
tS
time to peak temperature
(t 25ºC to peak)
Time
260°C Peak Temperature, 3 seconds max.
© 2019 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 11/21/19
Surface Mount Fuses
NANO2® > Slo-Blo® Fuse > 449 Series
Product Characteristics
Product Marking
Body: Ceramic
Terminations: Gold-plated Caps
Brand, Amperage Rating
Operating Temperature
-55°C to 125°C
Materials
Thermal Shock
Mechanical Shock
Moisture Sensitivity Level Level 1, J-STD-020
Solderability
Insulation Resistance
(after Opening)
MIL-STD-202, Method 208
MIL-STD-202, Method 302, Test Condition A
(10,000 ohms minimum)
Vibration
Moisture Resistance
Salt Spray
Resistance to Soldering Heat
Dimensions
Part Numbering System
1A
3.15
(.124")
1.96
(.077")
Recommended pad layout
0449
6.10 ± .20
(.240")
6.86
(.270")
2.95
(.116")
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
MIL-STD-202, Method 101, Test Condition
B (48hrs)
MIL-STD-202, Method 210, Test condition
B (10 sec at 260°C)
F
001.
M
R
Series
AMP Code*
Refer to Electrical characteristics table
T
1.45
(.057")
Quantity Code
M = 1000 pcs
2.69 ± .25
(.106")
Packaging Code
R = Tape and Reel
*Example:
0.375 Amp product is 0449.375MR (1 amp
product shown above).
2.69 ± .25
(.106")
Packaging
Packaging Option
Packaging Specification
Quantity
12mm Tape and Reel
EIA RS-481-2 (IEC 286, part 3)
1000
Quantity &
Packaging Code
MR
Disclaimer Notice - Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, automotive, military, aerospace, medical, life-saving, life-sustaining or nuclear facility applications,
devices intended for surgical implant into the body, or any other application in which the failure or lack of desired operation of the product may result in personal injury, death, or property damage) other than those expressly set forth
in applicable Littelfuse product documentation. Warranties granted by Littelfuse shall be deemed void for products used for any purpose not expressly set forth in applicable Littelfuse documentation. Littelfuse shall not be liable
for any claims or damages arising out of products used in applications not expressly intended by Littelfuse as set forth in applicable Littelfuse documentation. The sale and use of Littelfuse products is subject to Littelfuse Terms and
Conditions of Sale, unless otherwise agreed by Littelfuse. Information furnished is believed to be accurate and reliable. However, users should independently evaluate the suitability of and test each product selected for their own
applications. Littelfuse products are not designed for, and may not be used in, all applications. Read complete Disclaimer Notice at www.littelfuse.com/disclaimer-electronics.
© 2019 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 11/21/19
