The Working Principle of NTC thermistor

In numerous fields such as modern electronic devices, industrial control, and smart homes, temperature monitoring and regulation are crucial for ensuring the normal operation of equipment. NTC thermistor is high-precision and fast-response temperature sensing components, with the core feature that their resistance gradually decreases as the temperature rises.

1. Basic Concepts of NTC thermistor

NTC thermistor are electronic components made of semiconductor ceramic materials, primarily used to detect temperature changes and reflect the temperature trend through changes in resistance. Their core principle is based on the negative temperature coefficient effect, which is:

Temperature increase → Resistance decrease
Temperature decrease → Resistance increase

This characteristic makes NTC thermistor excel in applications requiring precise temperature detection and control, and they are widely used in medical equipment, automotive electronics, industrial automation, and household appliances.

2. Working Principle of NTC thermistor

1) Cause of the Negative Temperature Coefficient Effect
The working principle of NTC thermistor is based on the physical properties of their semiconductor materials, which are typically sintered from metal oxides such as manganese oxide, nickel oxide, cobalt oxide, and iron oxide. When the temperature rises, the number of charge carriers (free electrons or holes) in these metal oxides increases, enhancing conductivity and causing the resistance to decrease. Specifically:

At low temperatures: The semiconductor material has less electron activity, resulting in higher resistance.

At high temperatures: As the temperature rises, the semiconductor material has increased electron activity, and the resistance decreases accordingly.
This characteristic enables NTC thermistor to precisely sense temperature changes and output the signal as a change in resistance, which is used by electronic devices for temperature measurement and control.

2) Resistance-Temperature Relationship (R-T Characteristic)
The relationship between the resistance value R and temperature T of NTC thermistor can be described by the following exponential formula:

As can be seen from the formula, the larger the B value, the higher the sensitivity of the NTC thermistor to temperature changes, which means it is more suitable for applications that require precise temperature control. The NTC thermistor is a high-precision temperature sensing component that operates based on the negative temperature coefficient effect.

Its resistance value decreases as the temperature rises and is widely used in automotive electronics, medical equipment, household appliances, industrial control, and energy storage systems, among other fields. Due to its fast response, high precision, long-term stability, and low power consumption, the NTC thermistor has become a key component for temperature control in modern electronic devices.