An ultra low power temperature sensor for smart packaging monitoring

The work presented in this paper concerns the design and the characterization of a compact and low-power temperature CMOS sensor as part of an environmental monitoring scheme for MEMS devices. The proposed sensor is based on the TCR of available polysilicon resistances and a previously reported architecture (Active Bridge). It is composed of a single differential stage that performs both the resistance biasing and the amplification with the same 2μA current under 3.3V. Moreover, the Active Bridge offers the opportunity to implement a very compact ΣΔ modulator, thus converting the temperature input into digital information.