describe
A chip NTC thermistor is an electronic component using surface mount technology (SMT). Its core function is to sense ambient temperature and convert changes in it into a significant change in resistance. NTC stands for "Negative Temperature Coefficient," meaning its resistance decreases exponentially with increasing temperature.
This unique temperature-resistance characteristic makes it play a vital role as a "temperature sensor" and "protector" in modern electronic products.
Features
1. High sensitivity: It responds quickly to temperature changes and can detect small temperature fluctuations.
2. Miniaturization and standardization: It adopts standardized SMD packaging (such as 0402, 0603, 0805, etc.), which is compact and very suitable for high-density circuit board assembly, adapting to the development trend of light, thin and short electronic products.
3. High reliability and stability: Using advanced ceramic materials and manufacturing technology, it has good mechanical strength and long-term stability.
4. Lead-free and RoHS compliant: Meet environmental protection requirements.
Core working principle
Chip NTCs are made from metal oxides such as manganese, cobalt, and nickel, sintered at high temperatures. The relationship between their resistance (R) and absolute temperature (T) follows the Arrhenius law and can usually be described by a characteristic parameter (B value). Within a certain temperature range, their resistance-temperature characteristic curve exhibits a good exponential relationship.
Main Applications
Temperature monitoring and compensation: Used in mobile phones, laptops, battery management systems (BMS), etc. to monitor the temperature of key parts in real time to prevent overheating damage, and provide temperature compensation signals for other components (such as crystal oscillators and LCD screens).
Inrush Current Suppression: At the moment a power circuit starts up, the initial resistance of the NTC connected in series is high, effectively limiting the inrush current and protecting components such as the rectifier bridge and capacitors. After the current stabilizes, its resistance decreases due to self-heating, reducing power loss.
Household appliances: Widely used in home appliances such as air conditioners, refrigerators, and rice cookers as temperature sensors to control their working status.
Selection considerations
When choosing a chip NTC, you need to pay attention to the following parameters:
Nominal resistance (@25°C): The zero-power resistance value at an ambient temperature of 25°C, such as 10kΩ, 100kΩ.
B value: A key parameter that describes the sensitivity of resistance to temperature changes.
Precision: Resistance tolerance and B value tolerance.
Maximum power dissipation: The maximum power a component can withstand.
Operating temperature range: The ambient temperature range in which the component can work normally.
In summary, SMD NTC thermistors have become an indispensable basic component for temperature sensing and protection in modern electronic circuits with their small size, excellent performance and high reliability.
