Bourns gives its PWR163 power resistor a reverse-pin option
Bourns has added a reverse-pin version of its PWR163 DPAK power resistor, with reverse tape-and-reel and tube options to suit the new orientation. It is a modest addition to an established series, but a different terminal arrangement can be useful when the current path and available board space leave little freedom to reposition a power component.
The electrical specification remains familiar. The low-inductance surface-mount series has an isolated backplate and AEC-Q200 qualification, covering 0.02 Ω to 130 kΩ with ±1% or ±5% tolerance. Bourns specifies a temperature coefficient of ±100 ppm/°C and inductance no greater than 0.1 µH.
The thermal conditions deserve more attention than the 25 W headline alone suggests. That rating assumes a case held at 25°C, whereas the specified double-sided FR-4 test board supports 2.8 W at 25°C ambient. A board-mounted part cannot be assigned the larger figure without providing the thermal path needed to maintain the case temperature.
A packaging change with board-level consequences
The reverse-pin option gives the layout another orientation to work with, though the announcement does not establish an inherent electrical or thermal improvement. Any gain depends on how the terminals fit the current path and how heat leaves the backplate, through the interface and into the surrounding assembly.
The isolated backplate can be thermally coupled without making an electrical connection to the resistance element. With a specified junction-to-case thermal resistance of 5.2°C/W, the remaining thermal budget depends on the interface material, heat spreader and cooling conditions beyond the case.
Bourns identifies precharge, discharge and snubber circuits alongside automotive and industrial power electronics, cold-plate assemblies and high-frequency applications. Matching reverse packaging options accompany the part for automated assembly.
Sources
Image: Bourns. Bourns PWR163 series power resistor, series illustration rather than a confirmed photograph of the new reverse-pin option. https://www.bourns.com/news/new-products
