12.8 A BJT-based CMOS temperature sensor with a 3.6pJ·K2-resolution FoM

This paper presents a precision BJT-based temperature sensor implemented in standard CMOS. Its interface electronics consists of a continuous-time duty-cycle modulator [1], whose output can be easily interfaced to a microcontroller, rather than the discrete-time ΔΣ modulators of most previous work [2-4]. This approach leads to high resolution (3mK in a 2.2ms measurement time) and high energy efficiency, as expressed by a resolution FoM of 3.6pJK², which is a 3× improvement on the state of the art [4,5]. By employing chopping, dynamic element matching and a single room temperature trim, the sensor also achieves a spread of less than ±0.15°C (3σ) from -45 to 130°C.