Brochure

© 2017 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 03/03/17
Surface Mount Fuses
NANO
2®
> Slo-Blo
®
Fuse > 449 Series
Reflow Condition Pb – Free assembly
Pre Heat
- Temperature Min (T
s(min)
) 150°C
- Temperature Max (T
s(max)
) 200°C
- Time (Min to Max) (t
s
) 60 – 120 secs
Average ramp up rate (Liquidus Temp
(T
L
) to peak
3°C/second max.
T
S(max)
to T
L
- Ramp-up Rate 3°C/second max.
Reflow
- Temperature (T
L
) (Liquidus) 217°C
- Temperature (t
L
) 60 – 90 seconds
Peak Temperature (T
P
) 260
+0/–5
°C
Time within 5°C of actual peak
Temperature (t
p
)
20 – 40 seconds
Ramp-down Rate 5°C/second max.
Time 25°C to peak Temperature (T
P
) 8 minutes max.
Do not exceed 260°C
Soldering Parameters
Average Time Current CurvesTemperature Re-rating Curve
TIME IN SECONDS
CURRENT IN AMPERES
0.01
0.1
1
10
100
1000
0110 100
3A
4A
5A
1.5A
1A
.750A
.500A
.375A
2.5A
2A
3.5A
Note:
1. Rerating depicted in this curve is in addition to the standard derating of 25% for
continuous operation.
Wave Soldering Parameters
260°C Peak
Temperature,
3 seconds max.
Time
Temperature
T
P
T
L
T
S(max)
T
S(min)
25
t
P
t
L
t
S
time to peak temperature
(t 25ºC to peak)
Ramp-down
Ramp-up
Preheat
Critical Zone
T
L
to T
P