Murata ultra-compact and highly responsive PTC thermistor solution for space-limited designs


Murata has expanded its portfolio of positive temperature coefficient (PTC) surface-mount chip thermistors for overheat sensing by introducing the PRF03BB541NB7RL. These thermistors are optimised for incorporation into various forms of consumer electronic products and equipment such as wearable technology, smartphone handsets and tablets. Supplied in a ultra-compact format (with 0.6mm × 0.3mm × 0.3mm dimensions), they present engineers with the smallest overheat sensing solution currently available on the market.


The new thermistors directly benefit from Murata’s proprietary ceramic technology, with innovations being realised in relation to both the raw material composition and sintering procedure too. The result is that a significant downsizing can be achieved without any compromise in performance.

  • For mobile devices, the ultra-small size (0603M) facilitates high-density mounting and space limited design.
  • The PTC thermistor is ultra compact in size and highly responsive.
  • Do not generate any noise.
  • No complicated circuit structure is required. The number of components can be reduced.
  • After the heat is detected, it will automatically restore the original resistance value when it reaches the normal temperature, and it can be used repeatedly.
  • The resistance value is 540Ω at room temperature (25°C) while the resistance value is 4.7kΩ at a detection temperature of 115°C.

PTC is Positive Temperature Coefficient Thermistor. It is a thermistor with a characteristic that the resistance value increases sharply when the temperature exceeds a certain temperature. It is used to detect electronic equipment overheating or overcurrent protection.