LITTELFUSE 3425L300DR, 3425L300, 3425L250DR, 3425L250, 3425L200DR Datasheet

Resettable PTCs

250

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Surface Mount PTC

3425L Series

®

®

• The 3425L Series Resettable devices utilize a unique polymer-based,

Positive Temperature Coefficient (PTC) material to protect electrical
circuits against overcurrent conditions.

• In normal operation, the 3425L Series PTC has many conductive paths
and a very low resistance. In an overcurrent condition, the temperature
of the polymer material rises. This dramatically reduces the conductive
paths resulting in an immediate rise in resistance. In this condition, the
device provides circuit protection by significantly limiting the flow of
current. However, once the cause of the initial overcurrent condition is
eliminated, the 3425L Series PTC cools down and resets to a low
resistance value permitting the normal current flow to resume.

• The 3425L Series are surface mountable.

AGENCY APPROVALS: Recognized under the Components Program

of Underwriters Laboratory and the Component Acceptance Program of
CSA. TUV approved.

AGENCY FILE NUMBERS: UL E183209, CSA LR 108832

PHYSICAL SPECIFICATIONS:
Materials:

Terminal Material: Tin Plated Brass to MIL-T-10727B

Solderability: Meets EIA specification RS186-9E and IPC/EIA

J-STD-002, and IPC/EIA J-STD-001.

Device Labeling: Device is marked with the letter ‘L’, amperage rating

and date code.

Packaging: Packaged in tape and reel carrier per EIA 481-2 standard

Standard reel quantities:

ENVIRONMENTAL SPECIFICATIONS:

Passive Aging:

85°C, 1000 Hours.

Humidity Aging: 85°C, 85% R.H., 100 hours.
Thermal Shock: 85°C / –40°C, 20 times.

125°C / –55°C, 10 times.

Vibration: MIL-STD 202, Method 201. No resistance change.
Mechanical Shock: MIL-STD-202, Method 213 test condition I

(100 g’s, 6 sec.).

Operating/Storage Temperature: –40°C to 85°C Devices should

remain in sealed bags prior to use.

Part Reel Packaging

Number Quantity Suffix

3425L Series 1500 DR

-40 -30 -20 -10 0 10 20 30 40 50 60 70 80 85

0

90
80
70
60
50
40
30
20
10

100

130
120
110

140

150

160

Temperature (°C)

Percentage of Rated Current

Rerating Curve for 3425L Series

Surface Mount PTC

3425L Series

Resettable PTCs

251

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6

RESETTABLE PTCs

Dimensions (Inches)

MARKING

B

F

D

E

C

0.51-0.89

(.020-.035)

3.05

(.120)

0.635

(.025)

0.635
(.025)

A

Recommended Pad Layout (Inches)

All dimensions are nominal.

Series A B C D E F

3425L 6.70 max 9.50 max 3.68 4.572 2.29 10.67

(.264 max.) (.374 max.) (.145) (.180) (.090) (.420)

RECOMMENDED REFLOW CONDITIONS:

(IR, Forced Air Convection, Vapor Phase)
Devices are not designed to be wave soldered.

Catalog I

hold Itrip Vmax Imax Pd max. Current Time RIL RAT

Number (A) (A) (Vdc) (A) (W) (A) (Sec) (Ω)(Ω)

3425L150 1.50 3.0 15 40 1.9 8.0 5.0 0.060 0.25
3425L200 2.00 4.0 15 40 1.9 8.0 12.0 0.050 0.15
3425L250 2.50 5.0 15 40 1.9 8.0 25.0 0.035 0.10
3425L300 3.00 6.0 6 40 1.9 8.0 32.0 0.020 0.06

Maximum Time

To Tr ip

I

hold

= Hold Current: maximum current device will sustain for 4 hours without tripping in 20°C still air.

I

trip

= Trip Current: minimum current at which the device will trip in 20°C still air.

V

max

= Maximum voltage device can withstand without damage at rated current (Imax)

I

max

= Maximum fault current device can withstand without damage at rated voltage (Vmax)

P

d

= Power dissipated from device when in the tripped state at 20°C still air.

RI

L

= Minimum resistance of device in initial (un-soldered) state.

R

AT

= Maximum measured resistance in the non-tripped state 1 hour after reflow with reflow conditions of 260°C for 20 sec.

CAUTION: Operation beyond the specified ratings may result in damage and possible arcing and flame.

ORDERING INFORMATION:

Resistance

1.50A

2.00A

2.50A

3.00A

1001010.1

100

10

1

0.1

0.01

CURRENT IN AMPERES

TIME IN SECONDS

Average Time Current Curves