An ultra-low power dissipation CMOS temperature sensor with an inaccuracy of ±0.15 °C (3δ) from -40 °C to 125 °C.

An ultra-low power, high accuracy BJT-based CMOS temperature sensor is presented in this paper. The temperature sensor consists of analog front end (AFE) and hybrid ADC. In AFE design, two dynamic element matching (DEM) control modules are applied to current mirrors and bipolar transistors reduce the mismatch greatly and enhance the sensitivity of the temperature sensor. A hybrid ADC that combines ΣΔ ADC and SAR ADC is designed to provide quick conversion results and reduce the power dissipation. The proposed sensor is fabricated in a 0.18 μm CMOS process, occupying an area of 0.14 mm2. The measured results indicate that, the total current is 6.5 μA from a 1.8 V power supply, and achieves an inaccuracy of ±0.15 °C (3δ) from −40 °C to 125 °C.