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This paper presents a dual-microelectromechanical system (MEMS) resonator-based temperature sensor. In this sensor, the readout circuit estimates the temperature by measuring the frequency ratio of the two clocks generated by separate resonators with different temperature coefficients. The circuit is realized in a 0.18- \mu \textm CMOS process and achieves a resolution of 20 \mu \textK over a bandwidth of 100 Hz while consuming 19 mW of power, leading to a resolution FOM of 0.04 pJK2. It enables us to implement a MEMS-based programmable oscillator with an Allan deviation of <1 e^-10 over 1 s averaging time, and a frequency stability of <±0.1 parts per million in the temperature range from −45 °C to 105 °C. Such oscillators are key building blocks in telecom, datacom, and precision timekeeping applications. [ABSTRACT FROM AUTHOR]

This paper describes the design of a low power, energy-efficient CMOS smart temperature sensor intended for RFID temperature sensing. The BJT-based sensor employs an energy- efficient 2nd-order zoom ADC, which combines a coarse 5-bit SAR conversion with a fine 10-bit ΔΣ conversion. Moreover, a new integration scheme is proposed that halves the conversion time, while requiring no extra supply current. To meet the stringent cost constraints on RFID tags, a fast voltage calibration technique is used, which can be carried out in only 200 msec. After batch calibration and an individual room-temperature calibration, the sensor achieves an inaccuracy of \pm 0.15^\circ\C (3\sigma) from -55^\circ\C to 125^\circ\C. Over the same range, devices from a second lot achieved an inaccuracy of \pm 0.25^\circ\C (3\sigma) in both ceramic and plastic packages. The sensor occupies 0.08 \mm^2 in a 0.16 \mu\m CMOS process, draws 3.4 \mu\A from a 1.5 V to 2 V supply, and achieves a resolution of 20 mK in a conversion time of 5.3 msec. This corresponds to a minimum energy dissipation of 27 nJ per conversion. [ABSTRACT FROM AUTHOR]

This paper describes the design of a CMOS smart temperature sensor intended for RFID applications. The PNP-based sensor uses a digitally-assisted readout scheme that reduces the complexity and area of the analog circuitry and simplifies trimming. A key feature of this scheme is an energy-efficient two-step zoom ADC that combines a coarse 5-bit SAR conversion with a fine 10-bit \Sigma\Delta conversion. After a single trim at 30^\circ\C, the sensor achieves an inaccuracy of \pm 0.2^\circ\C (3\sigma) from -30^\circ\C to 125^\circ\C. It also achieves a resolution of 15 mK at a conversion rate of 10 Hz. The sensor occupies only 0.12 \mm^2 in a 0.16\ \mu\m CMOS process, and draws 4.6 \mu\A from a 1.6 V to 2 V supply. This corresponds to a minimum power dissipation of 7.4\ \mu\W, the lowest ever reported for a precision temperature sensor. [ABSTRACT FROM AUTHOR]