An NTC thermistor refers to a thermistor with a negative temperature coefficient. It is a high-performance ceramic with a structure close to the theoretical density using a single high-purity material. While achieving miniaturization, it has the characteristics of small resistance value and temperature characteristic fluctuation, and fast response to various temperature changes, enabling high-sensitivity and high-precision detection. Guangdong Nanfang Hongming provides small, high-reliability products of various shapes and characteristics, which can meet the application needs of our customers.

The working principle of NTC negative temperature coefficient thermistor

NTC is the abbreviation of Negative Temperature Coefficient, which means negative temperature coefficient. It generally refers to semiconductor materials or components with a large negative temperature coefficient. The so-called NTC thermistor is a negative temperature coefficient thermistor. It is made of metal oxides such as manganese, cobalt, nickel and copper as the main raw materials by ceramic technology. These metal oxides all have semiconductor properties because they are completely similar to semiconductor materials such as germanium and silicon in the way they conduct electricity. When the temperature is low, the number of carriers of these oxide materials decreases, so their resistance value is higher, and the number of carriers increases, so the resistance value decreases.

NTC negative temperature coefficient thermistor composition
NTC (Negative Temperature Coefficient) refers to the thermistor phenomenon and material whose resistance decreases exponentially with increasing temperature and has a negative temperature coefficient. The material is a semiconductor ceramic made of two or more metal oxides, such as manganese, copper, silicon, cobalt, iron, nickel, zinc, etc., which are fully mixed, formed, and sintered. It can be made into a negative temperature coefficient. (NTC) thermistor. The resistivity and material constant vary with the proportion of material composition, sintering atmosphere, sintering temperature and structural state. Now there are also non-oxide NTC thermistor materials represented by silicon carbide, tin selenide, tantalum nitride, etc.
Most of NTC thermal semiconducting ceramics are spinel structure or other structures with negative temperature coefficient. The resistance value can be approximately expressed as: RT and RT0 are the resistance values at temperature T and T0 respectively, and Bn is the material constant. The resistivity of the ceramic grain itself changes due to temperature changes, which is determined by the characteristics of the semiconductor. The rated zero-power resistance value is the resistance value R25 measured by the NTC thermistor at a reference temperature of 25 ℃, and this resistance value is the nominal resistance value of the NTC thermistor. The resistance value of the NTC thermistor is usually referred to as this value.

Main parameters of NTC negative temperature coefficient thermistor
Zero power resistance value RT (Ω)
RT refers to the resistance value measured at a specified temperature T with a measurement power that causes the change in resistance value to be negligible relative to the total measurement error.
The relationship between resistance value and temperature change is:
RT = RN expB(1/T – 1/TN)
RT : NTC thermistor resistance value at temperature T (K).
RN : NTC thermistor resistance value at rated temperature TN (K).
T: Specified temperature (K).
B: The material constant of the NTC thermistor, also known as the thermal index.
exp : The exponent to the base e of the natural number ( e = 2.71828 … ).
This relation is an empirical formula and is only accurate within a limited range of the rated temperature TN or the rated resistance value RN, since the material constant B is itself a function of the temperature T.
Rated zero-power resistance value R25 (Ω)
According to the national standard, the rated zero-power resistance value is the resistance value R25 measured by the NTC thermistor at the reference temperature of 25 ℃, and this resistance value is the nominal resistance value of the NTC thermistor. The resistance value of the NTC thermistor is usually referred to as this value. For commonly used NTC thermistors, the B value range is generally between 2000K ~ 6000K.