Calculate Junction Temperature
The following is a simple tool to help you evaluate the interplay of the various thermal design parameters that influence junction temperature. In the model, you can enter the thermal resistance values at each step of the path from the array itself to ambient air.
We have laid the model out in two columns. In the left column, you can enter a target junction temperature and calculate the required heat sink capacity. In the right column, you can enter a heat sink capacity and calculate the expected junction temperature.
In both cases, you can change your assumptions about ambient air temperature, type of thermal interface and level of input current. The two-column approach also makes it easy for you to verify maximum junction temperature at the highest expected ambient temperature, while cross-checking what temperatures you can expect on an ongoing basis under normal conditions.
Please feel free to contact us with any questions you might have. We look forward to helping you with your LED thermal management issues.