High-power ultra-low-ohmic shunt resistors dissipate 5W

April 10, 2014 // By Graham Prophet
Rohm’s shunt resistors are intended for current detection in applications with increased power requirements, such as automotive systems and industrial equipment. The new PSR series includes PSR400, which is rated at 4W, and PSR500, up to 5W.

These devices meet a requirement for high accuracy resistors with superior temperature coefficient of resistance (TCR), for stable operation in extreme temperature environments and that feature ultra-low resistance values in order to minimise power consumption.

High-yield precision welding technology enables guaranteed high rated power in the 5W class, while a high-performance alloy adopted for the resistive metal provides superior TCR in the low-ohmic region. This ensures sufficient margin even in applications with stringent temperature requirements, such as automotive systems and industrial equipment, while lightening design load.

To support high power and ensure high measurement accuracy even in the ultra-low-ohmic region (0.2 mΩ), technology for bonding copper electrodes without variations is required. Rohm employed original precision welding technology to join the resistive metal to thick copper electrodes, achieving high heat capacity with excellent thermal dissipation characteristics.

Rohm; www.rohm.com/web/eu