Power Dissipation: 5 V, 2 A, θ=30 °C/W
A 5 V, 2 A component dissipates 10 W, causing a 300 °C junction temperature rise at θJA=30 °C/W.
How to use this tool
- Enter voltage across component, current through component, resistance and thermal resistance (θ_ja) in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your power dissipated and the full breakdown beneath it.
USB-C power delivery regulators handling 5 V at 2 A must manage 10 W of dissipation — thermal analysis determines if a heatsink is needed.
Frequently asked questions
- What is thermal resistance (θ_JA)?
- It is the resistance to heat flow from the component junction (hottest point) to the ambient air, in °C/W. A small IC might have θ_JA = 100 °C/W; a power transistor on a heatsink might be 5 °C/W.
- How do I derate a component for safety?
- Most manufacturers recommend derating to 50–70% of the maximum rated power at 25 °C. Check the derating curve in the datasheet for operation at elevated ambient temperatures.