With the planned proliferation of the Internet-of-Things, billions of power limited wireless sensing devices are expected to be sold worldwide. Within that group is a large subset of applications in which temperature sensing will be important. Needed for this application space are ultra-small and ultra-low-power temperature sensors.
Researchers at UC San Diego have an invention which is a state-of-the-art CMOS temperature sensor operating in the sub-nanowatt regime. The design is fabricated in 65 nm CMOS and measurement from 8 samples reveal a maximum temperature error of +/-1.38 oC (+/-0.73 oC) and +0.77/-0.41 oC when operating from 0 to 100 oC after two-point (three-point) calibration without and with trimming, respectively. Operating from a 0.5 V supply, the 8 samples consumed an average power of 763 pW at 20 oC, which after a 0.3 s conversion time results in 230 pJ/conversion.
Application areas will include food safety, pharmaceutical processing and storage, industrial, commercial and home applications as well as animal health monitoring.
The lowest power temperature sensor developed to date that is compatible with standard CMOS processes.
A working prototype in silicon has been developed and is available for evaluation.
This invention is patent pending and available for licensing.
CMOS temperature sensor, fully integrated, internet of things, near-zero power sub-nW, temperature sensor, ultra-low power