Brochure
Table Of Contents
© 2017 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 03/03/17
Surface Mount Fuses
NANO
2®
Fuse > Very Fast-Acting > 448 Series
Average Time Current Curves
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
5°C/second max.
T
S(max)
to T
L
- Ramp-up Rate 5°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
Wave Soldering Parameters
260°C Peak
Temperature, 10
seconds max.
Soldering Parameters
Temperature Re-rating Curve
448 SERIES NANO LEAD FREE VERY FAST ACTING FUSE
0.001
0.01
0.1
1
10
100
00010010111.0
CURRENT IN AMPS
TIME IN SECONDS
.062 A
.080 A
.100 A
.125 A
.160 A
.200 A
.250 A
.315 A
.375 A
.40 A
.50 A
.63 A
.75 A
.80 A
1.00 A
1.25 A
1.50 A
1.60 A
2.00 A
2.50 A
3.00 A
3.15 A
3.50 A
4.00 A
5.00 A
6.30 A
7 A
8 A
10 A
12 A
15 A
Note:
1. Rerating depicted in this curve is in addition to the standard derating of 25% for
continuous operation.
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