PackagingMVP
Thermal budget
The maximum power a package can dissipate given its junction-to-ambient temperature margin and thermal resistance.
Inputs
Result
Enter values and calculate to see the result.
Interpretation
Enter the ambient and maximum junction temperatures and the thermal resistance.
Formula
P_allowable = (Tj_max − T_ambient) / Rθ
Simplified steady-state limit.
Variables
| Symbol | Variable | Unit |
|---|---|---|
| P_allowable | Maximum dissipated power | W |
| Tj_max | Maximum junction temperature | °C / K |
| T_ambient | Ambient temperature | °C / K |
| Rθ | Junction-to-ambient thermal resistance | °C/W |
Assumptions & validity
This tool assumes:
- Steady state; single junction-to-ambient thermal resistance.
- Uniform heating; no hotspots, transients, or design margin included.
Worked example
T_ambient = 25 °C, Tj_max = 125 °C, Rθ = 2 °C/W.
P = (125 − 25) / 2 = 50 W