A 210nW BJT-based Temperature Sensor with an Inaccuracy of ±0.15°C (3σ) from −15°C to 85°C

This paper presents a 210nW BJT-based temperature sensor that achieves an inaccuracy of ±0.15°C (3σ) from −15°C to 85°C. A dual-mode front-end (FE), which combines a bias circuit and a BJT core, halves the power needed to generate well-defined CTAT (V
BE
) and PTAT (ΔV
BE
) voltages. The use of a tracking ΔΣ ADC reduces FE signal swing and further reduces system power consumption. In a 180-nm BCD process, the prototype achieves a 15mK resolution in 50ms conversion time, translating into a state-of-the-art FoM of 2.3pJK
²
.