Semiconductor and component manufacturer Rohm has developed what it claims is the industry’s flattest metal plate shunt resistor. The PSR350 is just 0.85 mm high and is optimised for high-performance applications in automotive (and industrial) equipment.
Shunt resistors are used power modules for the main inverters of electric vehicles. These usually contain power devices (IGBTs and SiC MOSFETs). Increasingly, electronics designers are opting for low-profile, double-sided cooled designs to reduce package size.
Traditional metal plate shunt resistors reduce the cooling efficiency of power components due to their relatively high profile. However, reducing the height has proven difficult because prototypes must be developed and evaluated from a variety of weld materials in different configurations. Rohm is able to use its strengths in manufacturing and design to produce prototypes of various designs in small batches from a range of materials. This flexible design capability, tailored to market needs, enables the development of the flattest power shunt resistors on the market.
The PSR350 uses Rohm’s vertically integrated production system combined with material and process optimisation to achieve an overall height of only 0.85 mm, which is about half the height of conventional 12 W class products. The same technology is also used in the development of the industry’s smallest 15 W shunt resistor, the 6.4 mm x 6.4 mm PSR 330. Compared to conventional products in the same class, this reduces the size by approximately 65%, allowing for a smaller mounting footprint in a variety of high-power applications. In addition, the PSR100 will be available in a 0.2 mΩ model, which lowers the lower limit of the available 0.3 mΩ model, enabling the detection of even higher currents.
These products are suitable for detecting high currents in applications equipped with motors and/or lithium-ion batteries, such as electronic power steering, electric compressors, main inverters, on-board chargers (OBC), DC/DC converters, battery management systems (BMS)
https://www.rohm.com/products/resistors
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