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Silicon PTC
Thermistors
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- DO7 Glass Encapsulation
- Molded Epoxy Encapsulation
- Radial Leads
- Axial Leads
- SMD
- Telemetry
- Thermometry
- Temperature Regulation
- Over temperature Protection
- Amplifiers
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Description
The positive temperature coefficient of resistance is very large: approximately 0.7%/°C, making these units ideal for use in temperature compensating and sensing applications. Applications include amplifiers, power supplies, transducers, telemetry, computers, magnetic amplifiers, thermometry, meteorology, temperature regulation and over-temperature protection. Silicon PTC Specifications
| Style |
Wattage
Rating
@ 100°C
(Watts) |
Resistance
Range
(ohms) |
Thermal
Time
Constant
(Sec. Max) |
Operational
Ambient
Temperature
Range (°C) |
Temp. vs.
Coefficient of
Resistance
Table |
| DS125 |
0.125 |
10 to 39,000 |
34.8 |
-65 to +150 |
A |
| DS200 |
0.250 |
10 to 39,000 |
34.8 |
-65 to +150 |
A |
| DS250 |
0.250 |
10 to 39,000 |
54 |
-65 to +150 |
A |
| DG125 |
0.125 |
10 to 10,000 |
60 |
-65 to +125 |
B |
| DC125 |
0.125 |
10 to 10,000 |
54 |
-65 to +125 |
B |
| DU100 |
0.125 |
10 to 10,000 |
9 |
-65 to +125 |
B |
| RTH22ES |
0.250 |
10 to 10,000 |
34.8 |
-65 to +150 |
A |
| RTH42ES |
0.125 |
10 to 10,000 |
60 |
-65 to +125 |
B |
MlL-Approved Series
RTI Electronics' PTC thermistors are designed and built to withstand all environmental conditions required by the most stringent Mil specs. They meet or exceed all requirements of MIL-T-23648 for positive temperature coefficient thermistors.
RTH42ES - Per MIL-T-23648/19. Glass, hermetically sealed type, similar to DG125 series.
RTH22ES - Per MIL-T-23648/9. Molded style, similar to DS200 series. |
Styles and Dimensions |
| Temperature vs Coefficient of Resistance Tables |
| Table A |
TEMP.
°C |
Resistance Ranges @25°C |
10
to
75 |
82
to
160 |
180
to
620 |
680
to
1800 |
2000
to
12,000 |
15,000
to
39,000 |
| -55 |
0.615 |
0.582 |
0.560 |
0.550 |
0.515 |
0.481 |
| -15 |
0.790 |
0.770 |
0.755 |
0.740 |
0.730 |
0.712 |
| 0 |
0.863 |
0.847 |
0.838 |
0.835 |
0.825 |
0.814 |
| 25 |
1.000 |
1.000 |
1.000 |
1.000 |
1.000 |
1.000 |
| 50 |
1.160 |
1.170 |
1.180 |
1.200 |
1.230 |
1.210 |
| 75 |
1.350 |
1.370 |
1.400 |
1.420 |
1.450 |
1.430 |
| 100 |
1.545 |
1.584 |
1.623 |
1.656 |
1.670 |
1.670 |
| 125 |
1.750 |
1.800 |
1.860 |
1.920 |
1.960 |
N/A | |
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| Standard Resistance Values (Ohms) |
| 10 |
56 |
390 |
2,200 |
| 12 |
68 |
470 |
2,700 |
| 15 |
82 |
500 |
3,300 |
| 18 |
100 |
560 |
3,900 |
| 22 |
120 |
680 |
4,700 |
| 27 |
150 |
820 |
5,000 |
| 33 |
180 |
1,000 |
5,600 |
| 39 |
220 |
1,200 |
6,800 |
| 47 |
270 |
1,500 |
8,200 |
| 50 |
330 |
1,800 |
10,000 | |
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| Table B |
TEMP.
°C |
Resistance Ranges @ 25°C (ohms) |
10
to
75 |
82
to
160 |
180
to
510 |
560
to
1300 |
1500
to
6200 |
6800
to
10,000 |
| -55 |
0.615 |
0.582 |
0.560 |
0.550 |
0.515 |
0.510 |
| -15 |
0.790 |
0.770 |
0.755 |
0.740 |
0.730 |
0.730 |
| 0 |
0.863 |
0.847 |
0.838 |
0.835 |
0.825 |
0.825 |
| 25 |
1.000 |
1.000 |
1.000 |
1.000 |
1.000 |
1.000 |
| 50 |
1.160 |
1.170 |
1.180 |
1.200 |
1.230 |
1.190 |
| 75 |
1.350 |
1.370 |
1.400 |
1.420 |
1.450 |
1.400 |
| 100 |
1.545 |
1.584 |
1.623 |
1.656 |
1.670 |
1.610 |
| 125 |
1.750 |
1.800 |
1.860 |
1.920 |
1.960 |
1.830 | |
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| Table C |
Tolerance at Temperatures
Other Than 25°C |
Temp.
(°C) |
±5%
(J)* |
±10%
(K)* |
| -55 |
± 20 |
± 25 |
| -15 |
± 13 |
± 18 |
| 0 |
± 7 |
± 12 |
| 50 |
± 7 |
± 12 |
| 75 |
± 9 |
± 14 |
| 100 |
± 12 |
± 17 |
| 125 |
± 15 |
± 20 |
*Tolerance@25° |
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The tables above will give the resistance value ofthe thermistor for the listed temperatures (RT). To determine the resistance value of the thermistor at temperature (RT):
Find the temperature in the vertical column, "Temp. °C". Next find the resistance range of the thermistor at 25°C, (R25°C), in the appropriate vertical column. The intersection of the two columns will give the "coefficient of resistance", (Rc), of the thermistor at the desired temperature. Compute as follows:
RT = R25°C x Rc
Resistance tolerances for temperatures other than 25°C are shown in "Table C". For instance, the resistance tolerance at +50°C for a Silicon PTC Thermistor with a tolerance of ± 5% @ 25°C would be ± 7%. |
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Recommended Derating Curve
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Ordering Information
RTI Electronics' part number consists of a multi-digit alphanumeric code. The example shown here:
DG125 122k is the DG125 with resistance value of 1200 ohms and a tolerance of ±10%
Contact factory for more information. |
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