Compact and responsive PTC thermistor solution for space-limited designs

Murata has increased its portfolio of PTC surface-mount chip thermistors for overheat sensing by releasing the PRF03BB541NB7RL. These thermistors are optimised for inclusion into multiple forms of consumer electronic products and equipment including wearable technology, smartphone handsets and tablets.

Provided in a 0201 format (with 0.6mm x 0.3mm x 0.3mm dimensions), they claim to provide engineers with the smallest overheat sensing solution available on the market. The thermistors provide elevated levels of accuracy (±5C at lower sensing temperatures, and up to ±7C at higher sensing temperatures) as well as fast responsiveness. Their resistance values increase sharply once above the Curie temperature. This indicates that overheat situations can be met quickly, thereby diminishing the risk of damage to circuitry.

The new thermistors directly benefit from the company's proprietary ceramic technology, with innovations being realised about the raw material composition and sintering procedure. The result is that a meaningful downsizing can be accomplished with compromise in performance. Moreover, the thermistors have strong operational stability and do not create any noise which would otherwise affect neighbouring components.

The device displays industry-leading robustness. It has a maximum voltage rating of 32VDC and supports an extensive working temperature range of 20C to +150C.

“The increasing density of components in modern electronic designs makes dissipation of heat an ever-greater challenge,” states Takayuki Kaneko, general manager, RF Solutions and Functional Device Group at Murata Europe. “By using thermistors that take up less board footprint, it is possible to improve overheat sensing accuracy as they can be placed closer to the areas that need to be monitored. Specifying these components also enables a reduction in the overall bill-of-materials costs.”