Littelfuse 443 Series - Manual (Page 2)

© 2013 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 12/19/13
Surface Mount Fuses
NANO 2® > 250V > Time Lag > 443 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
Soldering Parameters
Temperature Rerating Curve
0.001
0.01
0.1
1
10
100
0.1 1 10 100 1000
TIME IN SECONDS
CURRENT IN AMPS
0.50
A
0.75
A
1.00
A
1.50
A
2.00
A
2.50
A
3.00
A
3.50
A
4.00
A
5.00
A
Note:
1. Derating 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
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