A single MOSFET can be employed as a thermal sensor to measure on-chip dynamic thermal signals caused by a power-dissipating CUT.

The measurement depends on the thermal properties of the substrate, the CUT-sensor distance, and the electrical properties of MOSFET sensor.

Thermal simulations in COMSOL and experimental results from a chip fabricated in 0.35 μm CMOS technology are provided.

The proposed thermal sensor is applied to estimate the linearity of an RF amplifier.