HEAT SINK CALCULATOR


CUI Devices' heat sink calculator can be used to quickly solve for a device’s junction temperature, power dissipation, and heat sink-to-ambient thermal impedance ratings. To use the calculator, enter your known values into the appropriate fields, click calculate, and the converted junction temperature, power dissipation, or thermal impedance heat sink-to-ambient value will be shown. These calculated values can then be used to specify the proper heat sink in a design. For more information on heat sink design, view our heat sink selection tutorial.

  • TJ = Junction Temperature (°C)
  • P = Power Dissipated (W)
  • RJ-C = Thermal Impedance Junction-to-Case (°C/Watt)
  • RC-S = Thermal Impedance Case-to-Sink (°C/Watt)
  • RS-A = Thermal Impedance Sink-to-Ambient (°C/Watt)
  • TA = Ambient Temperature (°C)

Thermal Impedance
Sink-to-Ambient



RS-A (°C/W)

Junction
Temperature



TJ (°C)

Power
Dissipated



P (W)

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