- What is an NTC Thermistor?
Negative Temperature Coefficient Thermistor -
NTC Thermistors are electronic components which reduce the resistance when the temperature increases. NTC Thermistors are used in various products.
Sintered non-oxide ceramic made of manganese (Mn) , nickel (Ni) , cobalt (Co) and other elements, are used as the material of NTC Thermistors. An electrode is formed in this ceramic. The lead type and chip type are common appearance shapes.
Resistance Temperature Characteristic
The resistance of NTC Thermistors decreases exponentially to the temperature, as shown in the following figure.
Since the resistance of NTC Thermistors can be expressed by the following formula, it is widely used as a temperature sensor.
In this formula, RT is the resistance when the ambient temperature is T (K) , R0 is the resistance when the ambient temperature is T0 (K) , and B is the constant called the B constant.
In addition, the B constant indicates a slope of the change in resistance of the Thermistor due to a temperature change, and is the basic characteristic of an NTC Thermistor.
Note that since the B constant changes slightly with the temperature, the value of the B constant changes by the defined temperature.
The resistance of NTC Thermistors changes by 3 to 5%/°C to the temperature change. This is used in many electronic devices as a general temperature sensor!
Example, Smart Phones;
When you are using a Smart Phone, have you ever experienced that the "body of the phone gets hot?"
It can be said that thin and highly efficient Smart Phones are small PCs. The body tends to become hot because unlike PCs, there is no fan or etc. to release the heat. Therefore, there is a risk of the precision components which are sensitive to heat being damaged.
The NTC Thermistors come into play in such conditions! !
NTC Thermistors measure the temperature inside Smart Phones, and perform various control using the temperature information.
Demonstration video about NTC Thermistors