Brochure

© 2017 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 03/03/17
Surface Mount Fuses
Thin Film > 1206 Size > Very Fast-Acting > 429 Series
Average Time Current Curves
7
A
TIME IN SECONDS
CURRENT IN AMPERES
0.01
0.1
0.1
1
1
10
100
10 10
0
0.0
01
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
) 250
+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 Re-rating Curve
Wave Soldering 260°C, 10 seconds max.
Note:
1. Rerating depicted in this curve is in addition to the standard derating of 25% for
continuous operation.
Example:
For continuous operation at 70 degrees celsius, the fuse should be deratedas follows:
I = (0.75)(0.80)I
RAT
= (0.60)I
RAT
2. The temperature derating curve represents the nominal conditions. For questions
about temperature derating curve, please consult Littelfuse technical support
for assistance.
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