Surface Mount Fuses
Introduction to Circuit Protection
NANO2® > 250V > Time Lag > 443 Series
Transientology
Temperature Rerating Curve
AverageTime Current Curves
100
10
1
0.1
/PUFꢑ
0.01
ꢆꢅꢀ %FSBUJOHꢀEFQJDUFEꢀJOꢀUIJTꢀDVSWFꢀJTꢀJOꢀBEEJUJPOꢀUPꢀUIFꢀTUBOEBSEꢀEFSBUJOHꢀPGꢀꢁꢂꢇꢀGPSꢀ
DPOUJOVPVTꢀPQFSBUJPOꢅ
0.001
0.1
1
10
100
1000
CURRENT IN AMPS
Soldering Parameters
tP
Reflow Condition
-Temperature Min (Ts(min)
1Cꢀoꢀ'SFFꢀBTTFNCMZ
TP
Critical Zone
TL to TP
Ramp-up
)
ꢆꢂꢃ¡$ꢀ
TL
TS(max)
Pre Heat -Temperature Max (Ts(max)
)
ꢁꢃꢃ¡$
tL
-Time (Min to Max) (ts)
ꢊꢃꢀoꢀꢆꢁꢃꢀTFDT
Ramp-down
Average ramp up rate (LiquidusTemp
(TL) to peak
Preheat
ꢂ¡$ꢏTFDPOEꢀNBYꢅ
TS(min)
tS
TS(max) toTL - Ramp-up Rate
ꢂ¡$ꢏTFDPOEꢀNBYꢅ
ꢁꢆꢋ¡$ꢀ
-Temperature (TL) (Liquidus)
Reflow
25
time to peak temperature
(t 25ºC to peak)
-Temperature (tL)
ꢊꢃꢀoꢀꢎꢃꢀTFDPOET
ꢁꢂꢃꢐꢃꢏꢄꢂꢀ¡$
Time
PeakTemperature (TP)
Time within 5°C of actual peak
Temperature (tp)
ꢁꢃꢀoꢀꢈꢃꢀTFDPOET
Ramp-down Rate
ꢂ¡$ꢏTFDPOEꢀNBYꢅ
ꢌꢀNJOVUFTꢀNBYꢅ
ꢁꢊꢃ¡$
Time 25°C to peakTemperature (TP)
Do not exceed
ꢁꢊꢃ¡$ꢀ1FBLꢀ
5FNQFSBUVSFꢉꢀ
ꢍꢀTFDPOETꢀNBYꢅ
Wave Soldering Parameters
© 2009 Littelfuse, Inc.
443 Series
74
Revised: March 17, 2009
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/443.html for current information.
LITTELFUSE [ LITTELFUSE ]
