A 0.008-mm2 area-optimized thermal-diffusivity-based temperature sensor in 160-nm CMOS for SoC thermal monitoring

An array of temperature sensors based on the temperature-dependent thermal diffusivity of bulk silicon has been realized in a standard 160-nm CMOS process. The sensors achieve an inaccuracy of ±2.4 °C (3σ) from -40 to 125 °C with no trimming and ±0.65 °C (3σ) with a one temperature trim. Each sensor occupies 0.008 mm², and achieves a resolution of 0.21 °C (rms) at 1 kSa/s. This combination of accuracy, speed, and small size makes such sensors well suited for thermal monitoring in microprocessors and other systems-on-chip.