Current-sensing resistors combine small package sizes and high power ratings

Innovative design enables the Susumu KRL series resistors to withstand thousands of temperature cycles. The Susumu portfolio of low-resistance current-sensing chip resistors includes the KRL series, which features the highest power ratings for the size of the products.

The KRL series resistors’ construction uses foil as the resistive material, and a face-down structure with a ceramic substrate on top. The benefit of positioning the ceramic substrate at the top of the package is that it dissipates heat to the ambient air, while the terminals at the bottom dissipate heat to the board, thus eliminating hot spots. In addition, terminals at the bottom provide the shortest possible electrical path from the resistive body to the board connections, minimizing the device’s temperature coefficient of resistance. 

The highly heat-conductive adhesive layer between the resistive foil and the ceramic substrate acts as a buffer for the stress created by the difference in temperature coefficient of expansion between the ceramic and a PCB’s FR-4 material. This means that the solder joint remains sound after thousands of temperature cycles.

The AEC-Q200-qualified KRL series resistors are offered in versions with terminals on the long or on the short side of the package, and as a precision four-terminal resistor. A low thermal electro-motive force type is also available.