The RHC series of thick-film, high-power chip resistors from Stackpole Electronics can dissipate 2 W in a 2512-size SMD package. Its unique design and specialized materials and processes yield a component that typically runs 30°C cooler than standard 2512 chips and has solder-joint temperatures well below the industry standard of 105°C for circuit boards. The resistors employ a special resistive element and coating that offer better heat transfer to the ambient air and are more tolerant of the higher temperatures associated with higher power. The RHC series is also trimmed to more evenly distribute heat over the surface of the resistive element rather than concentrate the heat at a hot spot as with normal calibration trims.
The resistors' maximum 5-s overload power is 70% higher than standard 2512 chips, and the devices show no additional resistance shift for the EIA 575 standard short-time overload test at the elevated power rating. E24 values from 0.1 Ω to 1 MΩ are available, with a continuous working voltage of 200 V. The RHC series is RoHS-compliant and is available in 4000-piece tape-and-reel configuration, with samples available in three to four weeks. The resistors cost $0.12 each for 5% tolerance and $0.18 each for 1% tolerance. For more information, go to www.seielect.com.