Resettable PPTC Datasheet
PolySwitch® Resettable PPTCs
Battery Strap > LR4 Series
Thermal Derating [Hold Current (A) at AmbientTemperature (°C)]
Maximum AmbientTemperature
Part
Description
Ordering Part
Number
-40°C
-20°C
0°C
20°C
25°C
40°C
50°C
60°C
70°C
80°C
85°C
Hold Current (A)
LR4-190F
LR4-260F
LR4-380F
LR4-380XF
LR4-450F
LR4-550F
LR4-600F
LR4-600XF
LR4-730F
LR4-900F
LR4-1300SSF
RF1538-000
RF1543-000
RF1536-000
E89591-000
RF1542-000
RF1545-000
RF1549-000
A77736-000
RF1547-000
RF2165-000
RF1550-000
2.8
3.8
5.4
5.4
6.5
7. 6
2.5
3.4
4.9
4.9
5.8
6.9
7. 8
2.3
3.1
4.4
4.4
5.3
6.2
7. 1
1.9
2.6
3.8
3.8
4.5
5.5
6.0
6.0
7. 3
1.86
2.54
3.64
3.64
4.38
5.32
5.86
5.86
7. 13
1.6
2.2
3.3
3.3
3.9
4.7
5.2
5.2
6.3
7. 5
1.5
2.0
3.0
3.0
3.6
4.3
4.7
4.7
5.7
6.8
10.3
1.4
1.9
2.8
2.8
3.3
4.0
4.4
4.4
5.4
6.2
9.5
1.2
1.7
2.5
2.5
2.9
3.6
3.9
3.9
4.7
5.5
8.6
1.1
1.4
2.3
2.3
2.6
3.2
3.4
3.4
4.2
4.9
7. 7
1.0
1.3
2.1
2.1
2.4
3.0
3.2
3.2
4.0
4.5
7. 2
8.7
8.7
10.5
12.7
17. 9
7. 8
7. 1
9.5
11.4
16.2
8.6
10.0
14.5
9.0
13.0
8.50
12.40
11.1
* Product electrical characteristics determined at 25°C.
Electrical Characteristics
IH
IT
VMAX
IMAX
(A)
PD MAX MaxTime-to-trip RMIN
RMAX R1MAX
(Ω) (Ω)
Part
Description
Ordering Part
Number
Typical Activation
Temperature
Typical
Resistance
(A)
(A)
3.9
(VDC
)
(W)
1.2
(A)
(s)
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
10.0
(Ω)
LR4-190F
LR4-260F
LR4-380F
LR4-380XF
LR4-450F
LR4-550F
LR4-600F
LR4-600XF
LR4-730F
LR4-900F
LR4-1300SSF
RF1538-000
RF1543-000
RF1536-000
E89591-000
RF1542-000
RF1545-000
RF1549-000
A77736-000
RF1547-000
RF2165-000
RF1550-000
1.90
2.60
3.80
3.80
4.50
5.50
6.00
6.00
7.30
9.00
13.00
15
100
100
100
100
100
100
100
100
100
100
100
9.5
0.0390 0.0720 0.102
0.0200 0.0420 0.063
0.0130 0.0260 0.037
0.0130 0.0260 0.037
0.0110 0.0200 0.028
0.0090 0.0160 0.022
0.0070 0.0140 0.019
0.0075 0.0140 0.019
0.0060 0.0120 0.015
0.0060 0.0100 0.014
0.0035 0.0065 0.009
125 °C
125 °C
125 °C
125 °C
125 °C
125 °C
125 °C
125 °C
125 °C
125 °C
125 °C
0.056
0.031
0.020
0.020
0.016
0.013
0.011
0.011
0.009
0.008
0.006
5.8
15
2.5
2.5
2.5
2.3
2.8
2.8
2.8
3.3
3.8
4.5
13.0
19.0
19.0
22.5
27.5
30.0
30.0
30.0
45.0
50.0
8.3
15
8.3
15
8.9
20
20
20
20
20
20
20
10.5
11.7
11.7
14.1
16.7
21.2
* Product electrical characteristics determined at 25°C.
Notes:
IMAX - Maximum fault current device can withstand without damage at rated voltage.
PD - Power dissipated from device when in the tripped state in 20°C still air unless otherwise specified.
RMIN - Minimum resistance of device as supplied at 20°C unless otherwise specified.
IH - Hold current: maximum current device will pass without interruption in 20°C still air unless otherwise
specified.
IT - Trip current: minimum current that will switch the device from low-resistance to high-resistance in 20°C still
air unless otherwise specified.
RMAX - Maximum resistance of device as supplied at 20°C unless otherwise specified.
R1MAX - Maximum resistance, measured at 20°C unless otherwise specified, of device one hour after being
VMAX - Maximum voltage device can withstand without damage at rated current.
gripped the first time.
Thermal Derating Curve
TypicalTime-to-Trip Curve at 20°C
200
180
160
140
120
100
80
G
F
100
H
E
D
I
B
A
C
10
1
G
A
F
E
I
D
C
H
B
0.10
0.01
60
40
1
10
100
20
Fault Current (A)
0
-50 -40 -30 -20 -10
0
10 20 30 40 50 60 70 80 90
A - LR4-190F
B - LR4-260F
C - LR4-380F
D - LR4-450F
E - LR4-550F
F - LR4-600F
G - LR4-730F
H - LR4-900F
- LR4-1300SSF
I
Temperature (˚C)
© 2022 Littelfuse, Inc.
Specifications are subject to change without notice.
2
Revised: GD. 08/16/22