Shunt resistors boast highest rated power for 2020 package
Claimed to deliver an industry-leading 4W (at an electrode temperature of 90 degrees C) in the compact 2010 package, measuring 5.0 x 2.5mm, the GMR50 series of shunt resistors is designed for current detection in motors and power supply circuits used in automotive systems and industrial equipment.
The shunt resistors, from Rohm Semiconductor, combines a revised electrode structure and design that improves heat dissipation to the PCB on which the resistor is mounted, says the company. It results in a 39 per cent reduction in mounting area over conventional 4W rated products, adds Rohm. The GMR50 shunt resistors are reliable, sustaining overcurrent loads and deliver stable current detection accuracy even when unexpected loads exceed the rated power.
Shunt resistors are typically used in the automotive and industrial markets for current detection. In the automotive sector, increasing functionality results in a greater number of motors and engine control units, while the mounting area for such applications is limited. Consequently, high density mounting is a growing trend, prompting the need for compact, power shunt resistors.
The GMR50 series continues the miniaturisation Rohm introduced with the GMR100 series. Like these 2515 type package power shunt resistors which measure 6.4 x 3.2mm, the GMR50 series benefits from improved heat dissipation by revising the electrode structure. Its heat dissipation results in what is believed to be the highest rated power (4W) in the 5.0 x 2.5mm package size at a terminal temperature of TK 90 degrees C and 3W at 110 degrees C.
Improving rated power makes it possible to use shunt resistors one size smaller in the 4W class to contribute to space saving design.
According to Rohm, the GMR50 series provides greater durability against overcurrent loads than conventional products, resulting in minimal resistance change even when overcurrent above the rating flows for stable current detection accuracy.
In addition to shunt resistors, Rohm can provide a broad portfolio ranging from ICs to power devices as well as advanced technical support such as thermal simulation.
For example, with the newly developed GMR50 series mounted on a PCB, it is possible to simulate surface temperature rise in comparison with Rohm’s conventional products. The simulation result suggests that it is able to suppress temperature rise over circuits that use two conventional 5025 size resistors in parallel, even when mounting just one unit.
