Surface Mount Fuses
Introduction to Circuit Protection
Transientology
Ceramic Fuse > 441 Series
Temperature Rerating Curve
Average Time Current Curves
2.5A
3A
3.5A
4A
5A
6A
10
CURRENT IN AMPERES
140
100
PERCENT OF RATING
120
10
100
80
TIME IN SECONDS
1
60
40
-65
-45
-25
-5
15
35
55
75
95
115
135
155
TEMPERATURE (°C)
0.1
Note:
1. Rerating depicted in this curve is in addition to the standard rerating of 20% for
continuous operation.
For continuous operation at 75 degrees celsius, the fuse should be rerated as follows:
I = (0.80)(0.85)I
RAT
= (0.68)I
RAT
0.001
1
100
0.01
Soldering Parameters
Reflow Condition
- Temperature Min (T
s(min)
)
Pre Heat
- Temperature Max (T
s(max)
)
- Time (Min to Max) (t
s
)
Average Ramp-up Rate (Liquidus Temp
(T
L
) to peak)
T
S(max)
to T
L
- Ramp-up Rate
Reflow
- Temperature (T
L
) (Liquidus)
- Temperature (t
L
)
260
+0/-5
°C
3°C/second max.
5°C/second max.
217°C
150°C
2A
T
P
Ramp-up
t
P
Critical Zone
T
L
to T
P
Temperature
200°C
T
L
T
S(max)
Preheat
t
L
Ramp-down
T
S(min)
t
S
25
time to peak temperature
(t 25ºC to peak)
Time
Peak Temperature (T
P
)
Time within 5°C of actual peak
Temperature (t
p
)
Ramp-down Rate
Time 25°C to peak Temperature (T
P
)
Do not exceed
6°C/second max.
8 minutes max.
260°C
Wave Soldering
260°C, 10 seconds max.
441 Series
2
© 2009 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/441.html for current information.
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