Rohm’s new shunt resistors contribute to greater miniaturisation
Rohm has added three new products featuring a rated power of 5W in resistance values of 0.5mΩ, 1.0mΩ, 1.5mΩ to the 2512-size (0.25inch × 0.12inch) / 6432-size (6.4mm × 3.2mm) PMR100 series of standard type metal plate shunt resistors designed for motor control and power circuits in automotive, consumer, and industrial equipment applications.
Shunt resistors for current detection are primarily used for power supply overcurrent protection, battery level detection, and in motor drive circuits in a wide range of fields, including the automotive, industrial equipment, and consumer electronics sectors. To achieve power savings required for various applications, precise circuit control using high accuracy high reliability shunt resistors is necessary. On top, as application functionality improves, boards are becoming denser, 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 utilising 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. 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 a variety of applications. Additionally, a rated terminal temperature of 130°C (for 0.5mΩ and 1mΩ products) and operating temperature range from -65°C to +175°C are guaranteed, ensuring stable operation even in extreme temperature environments. An excellent temperature coefficient of resistance (TCR) of ±75ppm/°C enables reliable, high accuracy current detection.
By further increasing the power and resistance ranges, Rohm is able to expand the PMR100 series to include compact, high power, high temperature, high accuracy models as well as 4W types in the smaller 1210-size (0.12inch × 0.1inch) / 3225-size (3.2mm × 2.5mm) and 2010-size (0.2inch × 0.1inch) / 5025-size (5.0mm × 2.5mm).
