Littelfuse 448 Series - Manual (Page 3)

© 2013 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 12/19/13
Surface Mount Fuses
NANO 2® > 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 Rerating Curve 448 SERIES NANO LEAD FREE VERY FAST ACTING FUSE
0.001
0.01
0.1
1
10
100
0 0 0 1 0 0 1 0 1 1 1 . 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. Derating depicted in this curve is in addition to the standard derating of 25% for
continuous operation.
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