33
© 2009 Littelfuse, Inc.
Specications are subject to change without notice.
Surface Mount Fuses
429 Series
Thin Film > 1206 Size > Very Fast-Acting > 429 Series
Please refer to www.littelfuse.com/series/429.html for current information.
429 Series
429 Series Fuse
Description
The 429 Series Fast-Acting SMF is a small (1206 size) thin-
lm device designed for secondary protection of circuits
used in space constrained applications such as hand-held
portable electronic devices.
This series is Halogen-Free, Lead-Free and meets the
requirements of the RoHS directive.
Agency Approvals
AGENCY AGENCY FILE NUMBER AMPERE RANGE
E10480 7A
LR29862 7A
Electrical Characteristics for Series
Features
• RoHScompliantand
Lead-Free 7A device
available-add ‘L’ sufx
to part number.
• Halogen-Free7A
device available-add
‘HF’ sufx to the part
number
• For new designs up
to 5A please consult
the 433 or 466 Series
% of Ampere
Rating Opening Time at 25OC
100% 4 hours, Minimum
200% 5 sec., Maximum
300% 0.2 sec., Maximum
Applications
Ampere
Rating
(A)
Amp
Code
Max
Voltage
Rating
(V)
Interrupting
Rating
Nominal Cold
Resistance
(Ohms)
Nominal
Melting
I2t (A2sec)
Agency
Approvals
7.00 007. 24 35 amperes
@ voltage, VAC/VDC 0.00925 3.6000 x x
Electrical Specications by Item
1. Measured at 10% of rated current, 25ºC.
2. Measured at rated voltage.
• Cellphones
• Batterypacks
• Digitalcameras
• DVDplayers
• Harddiskdrives.
Secondary protection for space constrained applications
such as:
Revised: Jun 16 , 2011
Introduction to Circuit Protection
Introduction to Circuit Protection
Transientology
34 © 2009 Littelfuse, Inc.
Specications are subject to change without notice.
Surface Mount Fuses
429 Series
Thin Film > 1206 Size > Very Fast-Acting > 429 Series
Please refer to www.littelfuse.com/series/429.html for current information.
Average Time Current Curves
7A
TIM E IN SEC O N D S
CURRENT IN AMPERES
0.01
0.1
0.1
1
1
10
100
10 100
0.001
Reow Condition Pb – Free assembly
Pre Heat
- Temperature Min (Ts(min))150°C
- Temperature Max (Ts(max))200°C
- Time (Min to Max) (ts)60 – 180 secs
Average ramp up rate (Liquidus Temp
(TL) to peak 5°C/second max
TS(max) to TL - Ramp-up Rate 5°C/second max
Reow - Temperature (TL) (Liquidus) 217°C
- Temperature (tL)60 – 150 seconds
Peak Temperature (TP)250+0/-5 °C
Time within 5°C of actual peak
Temperature (tp)20 – 40 seconds
Ramp-down Rate 5°C/second max
Time 25°C to peak Temperature (TP)8 minutes Max.
Do not exceed 260°C
Soldering Parameters
Temperature Rerating Curve
Wave Soldering 260°C, 10 seconds max.
Note:
1. Derating 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)IRAT = (0.60)IR AT
2. The temperature derating curve represents the nominal conditions. For questions
about temperature derating curve, please consult Littelfuse technical support
for assistance.
Time
Temperature
TP
TL
TS(max)
TS(min)
25
tP
tL
tS
time to peak temperature
(t 25ºC to peak)
Ramp-down
Ramp-up
Preheat
Critical Zone
TL to TP
35
© 2009 Littelfuse, Inc.
Specications are subject to change without notice.
Surface Mount Fuses
429 Series
Thin Film > 1206 Size > Very Fast-Acting > 429 Series
Please refer to www.littelfuse.com/series/429.html for current information.
429 Series
Materials
Body: Epoxy Substrate
Terminations, RoHS Compliant Device (429L):
100%TinoverNickeloverCopper
Element Cover Coat: Conformal Coating
NOTE: Do not use alcohol-based cleaners or
solvents with 429 Series Thin-Film Fuses as it
may damage the coating.
Operating
Temperature
– 55OC to 90OC.
Consult temperature rerating chart.
For operation above 90°C contact Littelfuse.
Thermal Shock Withstands 5 cycles of – 55OC to 125OC
Humidity MIL-STD-202F,Method103B
Condition D
Vibration
Withstands 10 – 55 Hz per MIL-STD-
202F, Method 201A and 10-2000 Hz
at 20 G’s per MIL-STD-202F, Method
204D, Condition D.
Insulation Resistance
(After Opening) Greater than 10,000 ohms
Resistance to
Soldering Heat
MIL-STD-202G, Method 210F,
Condition D
Product Characteristics
Dimensions
REFLOW SOLD ER
RECOMMENDED PAD LAYO UTS
3.81
(.150")
1.52
(.060")
2.03
(.080")
.635
(.025")
1.14
(.045")
2.49 (.098")
REF.
1.52
(.060")
3.18
(.125")
1.14
(.045")
1.12
(.044")
REF.
Part Numbering System
Packaging
Part Marking System
Packaging Option Packaging Specication Quantity Quantity &
Packaging Code
Tape & Reel – 8mm tape EIA-481 Rev. D (IEC 60286, part 3) 3000 WRM
Series Marking
Code
429L 7
0429 007. WRM L HF
SERIES
AMP Code
QUANTITY Code
L = Lead-Free device and
RoHS compliant device
Refer to Amp Code Column of
Electrical characteristics table
WRM = 3000 pieces, Tape and Reel
Halogen-Free item