Vishay Intertechnology has introduced the Vishay Sfernice D2TO35S, an automotive-grade thick-film power resistor designed with top-side cooling. The surface-mount device dissipates heat directly through a heatsink mounted on its top surface, significantly reducing thermal stress on the PCB.

Vishay Sfernice D2TO35S top-side cooled power resistor in TO-263 package
Key Characteristics
- Power dissipation: up to 35 W at 25 °C (with specified conditions)
- Cooling method: Top-side cooling — heat transferred directly to an external heatsink
- Power density advantage: up to 9× higher power dissipation compared with standard PCB-mounted resistors when used with a heatsink
- Package: TO-263 (D²PAK)
- Resistance range: 4.7 Ω to 550 kΩ
- Tolerance: down to ±1%
- Thermal resistance: 4.28 °C/W
- TCR: down to ±150 ppm/°C
- Operating temperature range: −55 °C to +175 °C
- Construction: Non-inductive design
- Automotive-grade
- RoHS compliant
- Reflow soldering capability: up to 270 °C for 10 seconds
By directing heat away from the PCB, the D2TO35S allows designers either to increase power handling within the same board footprint or to reduce the space occupied by the resistor while maintaining the required power level. Lower PCB temperatures also reduce thermal stress on surrounding components.
Target Applications
- Automotive power circuits requiring high power dissipation
- Systems with strict PCB space constraints
- Circuits exposed to fast transient conditions (thanks to non-inductive design)
- Applications where thermal management and signal integrity are critical
Source: Electronics For You
