Littelfuse 456 Series - Manual (Page 2)

© 2013 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 12/19/13
Surface Mount Fuses
NANO 2® > 456 Series
Average Time Current Curves Temperature Rerating Curve
PERCENT OF UPRA
TING
PERCENT OF DOWNUPRA
TING
AMBIENT TEMPERATURE
248°F 212°F 176°F 140°F 104°F 68°F 32°F -4°F -40°F -76°F
120°C
264°F
140°C 100°C 80°C 60°C 40°C 20°C 0°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
Te
mperatur
e
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