Murata cuts thermistor mounting area by 60% with a 0.25mm device
Murata has developed a thermistor small enough to place in gaps that its previous smallest temperature sensor could not occupy. The NCU01 measures 0.25 × 0.125mm and reduces mounting area by approximately 60% against the company’s 0.4 × 0.2mm device.
The new series uses the 008004-inch package size, also described as 0201M in metric notation. Despite the reduction, it retains the ±1% resistance and ±1% B-constant tolerances of Murata’s larger 01005-inch product. Murata calls it the world’s smallest NTC thermistor, based on its own research.
Those two tolerances describe different parts of the temperature measurement. Resistance tolerance concerns the specified resistance value; the B constant characterises the slope of the resistance-versus-temperature relationship. Neither figure, taken alone, means that the finished circuit measures temperature to ±1%.
An NTC thermistor’s resistance falls as its temperature rises. A circuit can read that change using a resistor divider and an analogue input, with the conversion to temperature handled elsewhere. The sensing current also generates heat within the thermistor, so measurement conditions affect the result. Murata’s technical guidance treats self-heating separately from the resistance-temperature characteristic.
Murata identifies placement closer to heat-generating components as a use for the reduced mounting area. The package can occupy locations that would otherwise be difficult to accommodate with a larger thermistor.
Sample shipments are planned for October, with mass production scheduled during 2027.
