New shunt resistors contribute to greater miniaturisation

ROHM has added three new products featuring a rated power of 5W in resistance values of 0.5mOh, 1.0mOhm, and 1.5mOhm to the 2512-size (0.25" × 0.12")/6432-size (6.4mm × 3.2mm) PMR100 series of standard type metal plate shunt resistors developed for motor control and power circuits in automotive, consumer, and industrial equipment applications.

Shunt resistors for current detection are mainly used for power supply overcurrent protection and battery level detection, as well as motor drive circuits in various fields, including the automotive, industrial equipment, and consumer electronics sectors. Precise circuit control using high-accuracy, high-reliability shunt resistors is necessary to achieve the power savings required for various applications. On top of that, boards are becoming denser as application functionality improves, requiring smaller, higher-power shunt resistors. Particularly in the automotive field, it is important to ensure high detection accuracy even under high-temperature environments.

These new products achieve a rated power of 5W by using new materials with excellent temperature characteristics and terminal temperature derating. This represents the best-in-class for 6432-size flat chip types with protective film. They are achieving approx. 2.5 times higher rated power than conventional PMR100 2W products and around 1.7 times higher than 3W models makes it possible to replace larger high-power types – contributing to greater miniaturisation in various applications. A rated terminal temperature of 130C (for 0.5mOhm and 1mOhm products) and operating temperature range from -65C to +175C are guaranteed, ensuring stable operation even in extreme temperature environments. An excellent TCR of ±75ppm/C enables reliable, high-accuracy current detection.

The company continues to advance the development of resistors. By further increasing the power and resistance ranges, it is able to expand the series to include compact, high-power, high-temperature, high-accuracy models as well as 4W types in the smaller 1210-size (0.12" × 0.1")/3225-size (3.2mm × 2.5mm) and 2010-size (0.2" × 0.1")/5025-size (5mm × 2.5mm).

The new products are universally compatible with current sensing in various applications:

Automotive: EPS, electric compressors, oil/water pumps, door motors, ADAS controllers, etc.Industrial Equipment: Industrial power modules, power conditioners, power tools, PV inverters, server power supplies, UPS, base station power supplies, etc. Consumer applications: Home appliances (e.g. Air conditioners, refrigerators, vacuum cleaners, washing machines) etc.