TDP (thermal design power)
Beginner
The amount of power, and so heat, a chip is designed to give off steadily without overheating.
Novice
The steady power that the chip’s case and cooling are designed to carry away as heat while keeping the transistors below their maximum safe temperature. It is the chip’s power allowance for long-running work.
Expert
A thermal number, not a peak electrical one. Short bursts can exceed it, because the chip and its cooling take time to heat up; the largest instantaneous current is a separate requirement for the power-delivery design. It follows from the package’s thermal resistance (degrees of temperature rise per watt), the ambient temperature and the maximum junction temperature.