Brochure

© 2017 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 03/03/17
Surface Mount Fuses
NANO
2®
> Very Fast Acting Fuse > 456 Series
Average Time Current CurvesTemperature Re-rating Curve
PERCENT OF UPRATING
PERCENT OF DOWNUPRA
TING
AMBIENT TEMPERATURE
248°F212°F176°F140°F104°F68°F32°F-4°F-40°F-76°F
120°C
264°F
140°C100°C80°C60°C40°C20°C0°C-20°C-40°C-60°C
0 0
20
40
60
20
40
60
Soldering Parameters – Reflow Soldering
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 – 180 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 – 150 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
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
0.01
0.1
1
10
100
1 10 100 1000
TIME IN SECONDS
CURRENT IN AMPS
40A 30A 20A 25A
1000
Note:
1. Rerating depicted in this curve is in addition to the standard derating of 25% for
continuous operation.