Low-resistance shunt resistors shrink high-power applications
In recent years, the requirements for lower current consumption in high-power applications in the automotive and industrial sectors have increased. This requires shunt resistors that support high performance and precise current sensing. Rohm’s GMR and PSR series shunt resistors provide highly accurate current protection even at high temperatures.
The newly developed GMR320 series offers resistance values in the range of 5 Ω to 100 Ω and a rated power of 10 W with a size of 7142. Their resistance tolerance is specified as F (±1 %). The temperature coefficient (TCR) is ±25 ppm/°C. The operating temperature range is between -65 °C and +170 °C. The GMR320 series is thus suitable for automotive applications such as engine control units and headlights as well as for motors and power supplies in industrial plants and household appliances. Thanks to a special design and optimised materials, the GMR320 series can reduce the temperature rise by 23 % compared to standard shunt resistors and ensure high resistance to overcurrent loads. At the same time, it has the smallest dimensions among 10 W class resistors on the market. In addition, a high-performance metal alloy resistor element ensures a low temperature coefficient (TCR), which enables reliable and highly accurate current sensing even at low resistance values.
In the PSR series, which is often used as a high-power shunt resistor, Rohm has also increased the maximum rated power up to 15 W and improved the TCR value by lowering the terminal temperature. The PSR series features extremely low resistance values from 0.1 mΩ to 3.0 mΩ, a higher rated power and high current sensing accuracy in a compact package. Like the GMR series, it thus contributes to further miniaturisation in automotive and industrial applications.