A CMOS temperature sensor with an energy-efficient zoom ADC and an Inaccuracy of ±0.25°C (3s) from −40°C to 125°C

This paper describes a CMOS temperature sensor intended for RFID applications. The sensor achieves an inaccuracy of ±.25°C (3s) from −40°C to 125°C, while using 7× less energy than state-of-the-art sensors with similar accuracy [1]. Its energy efficiency is achieved by the use of a zoom ADC that combines a coarse SAR conversion with a fine ΔΣ conversion, while its accuracy is achieved by the use of various dynamic error correction techniques and a single room-temperature trim.

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