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RESETTABLE PTCs
SURFACE MOUNT PTC
2029L/3425L Series
• The 2029L/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 2029L/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 2029L/3425L Series PTC cools down and resets to a
low resistance value permitting the normal current flow
to resume.
• The 2029L/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
Lead Solderability: Meets EIA specification RS186-9E
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. ±5% typical resistance
change.
Humidity Aging: 85°C, 85% R.H., 1000 hours. ±5% typi-
cal resistance change.
Thermal Shock: 85°C / –40°C, 20 times. ±10% typical
resistance change.
Vibration: MIL-STD 202, Method 201. No resistance
change.
Mechanical Shock: MIL-STD-202, Method 213 test condi-
tion I (100 g’s, 6 sec.). No resistance change.
Max. Surface Temperature: 125°C
Operating/Storage Temperature: –40°C to 85°C
Part Reel Packaging
Number Quantity Suffix
2029L Series 2000 PR
3425L Series 1500 DR
Rerating Curve for 2029L /3425L Series
For NEW Designs use 1812L series PTC in place of the 2029L
Series.
OBSOLETE
PART
200
150
100
50
Percentage of Rated Current
0
-40-30-20-10 0102030405060708090
Temperature (°C)

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RESETTABLE PTCs
SURFACE MOUNT PTC
2029L/3425L Series
Dimensions (Inches)
MARKING
B
F
D
E
C
.020-.035
.120
.025
* .025
A
Recommended Pad Layout (Inches)
All dimensions are nominal.
Series A B C D E F
2029L .214 max. .314 max. .090 .120 .090 .380
3425L .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.
*0.010 for 2029L050
Catalog I
hold Itrip Vmax Imax Pd max. Current Time RIL RAT
Number (A) (A) (Vdc) (A) (W) (A) (Sec) (Ω)(Ω)
2029L030 0.30 0.6 60 10 1.7 1.5 3.0 1.200 4.80
2029L050 0.50 1.0 60 10 1.7 2.5 4.0 0.350 1.40
2029L075 0.75 1.5 30 40 1.7 8.0 0.3 0.350 1.00
2029S100 1.10 2.2 15 40 1.7 8.0 0.5 0.120 0.48
2029L100 1.10 2.2 30 40 1.7 8.0 0.5 0.120 0.48
2029L125 1.25 2.5 15 40 1.7 8.0 2.0 0.070 0.25
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 0.13
3425L250 2.50 5.0 15 40 1.9 8.0 25.0 0.035 0.09
2029L260 2.60 5.2 6.0 40 1.7 8.0 20.0 0.025 0.075
Maximum Time
To Trip
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 (I
max
)
I
max
= Maximum fault current device can withstand without damage at rated voltage (V
max
)
Pd= Power dissipated from device when in the tripped state at 20°C still air.
RIL= Minimum resistance of device in initial (un-soldered) state.
RAT= Maximum resistance of device at 20°C measured one hour after tripping or reflow soldering of 260°C for 20 sec.
CAUTION: Operation beyond the specified ratings may result in damage and possible arcing and flame.
ORDERING INFORMATION:
Resistance
Average Time Current Curves
OBSOLETE
PART
.500A
100
10
1
TIME IN SECONDS
0.1
0.01
.300A
CURRENT IN AMPERES
.750A
1.00A
1.50A
1.25A
2.00A
2.50A
1001010.1