Littelfuse 429 User Manual

Surface Mount Fuses

Thin Film > 1206 Size > Very Fast-Acting > 429 Series

429 Series Fuse

Description

The 429 Series Fast-Acting SMF is a small (1206 size) thin­film 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.

Features

Agency Approvals

AGENCY AGENCY FILE NUMBER AMPERE RANGE

E10480 7A

LR29862 7A

Electrical Characteristics for Series

% of Ampere

Rating

100% 4 hours, Minimum

200% 5 sec., Maximum

300% 0.2 sec., Maximum

Opening Time at 25

O

C

• RoHScompliantand

Lead-Free 7A device
available-add ‘L’ suffix to

• For new designs up to
5A please consult the
433 or 466 Series

part number.

• Halogen-Free7Adevice

available-add ‘HF’ suffix
to the part number

Applications

Secondary protection for space constrained applications
such as:

• Cellphones

• Batterypacks

• DVDplayers

• Harddiskdrives.

• Digitalcameras

Additional Information

Datasheet

Resources

Samples

Electrical Specifications by Item

Ampere

Rating

(A)

7. 0 0 0 0 7. 24

1. Measured at 10% of rated current, 25ºC.

2. Measured at rated voltage.

© 2013 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 12/19/13

Amp

Code

Max

Voltage Rating

(V)

Interrupting

Rating

35 amperes

@ voltage, VAC/VDC

Nominal Cold

Resistance (Ohms)

0.00925 3.6000

Nominal

Melting

2

t (A2sec)

I

Agency

Approvals

x x

Surface Mount Fuses

A

CURRENT IN AMPERES

0

0.0

Thin Film > 1206 Size > Very Fast-Acting > 429 Series

Temperature Rerating Curve

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)I

2. The temperature derating curve represents the nominal conditions. For questions
about temperature derating curve, please consult Littelfuse technical support
for assistance.

= (0.60)I

RAT

RAT

Average Time Current Curves

100

10

1

TIME IN SECONDS

0.1

0.01

01

0.1

1

7

10 10

Soldering Parameters

Reflow Condition Pb – Free assembly

- Temperature Min (T

Pre Heat

- Temperature Max (T

- Time (Min to Max) (ts) 60 – 180 secs

Average ramp up rate (Liquidus Temp
(T

) to peak

L

to TL - Ramp-up Rate 5°C/second max

T

S(max)

Reflow

- Temperature (TL) (Liquidus) 217°C

- Temperature (tL) 60 – 150 seconds

Peak Temperature (TP) 250

Time within 5°C of actual peak
Temperature (t

)

p

Ramp-down Rate 5°C/second max

Time 25°C to peak Temperature (T
Do not exceed 260°C

Wave Soldering 260°C, 10 seconds max.

) 150°C

s(min)

) 200°C

s(max)

5°C/second max

+0/-5

°C

20 – 40 seconds

) 8 minutes Max.

P

T

Temperature

S(max)

T

S(min)

T

P

T

L

25

time to peak temperature

Preheat

t

S

(t 25ºC to peak)

Ramp-up

t

P

Critical Zone

T

to T

L

P

t

L

Ramp-down

Time

Specifications are subject to change without notice.

© 2013 Littelfuse, Inc.

Revised: 12/19/13