A batteryless temperature sensor based on high temperature sensitive material

Precision high temperature sensors often require temperature compensation. Quartzdyne pressure transducers use a temperature sensitive quartz crystal for compensation. In an effort to shrink transducer packaging, and increase reliability; a prototype frequency output temperature sensor was designed using a 0.8um silicon bulk CMOS process. The 250°C operational sensor is based on a PTAT current generator. The design uses high temperature design techniques that were proven reliable in prior Quartzdyne ASIC's. The output frequency is 34kHz at 30°C, with a sensitivity of 100Hz/°C and achievable accuracy of ±0.3°C from 25°C to 200°C. This paper will review the sensor's characteristics, including the output linearity, hysteresis, accelerated aging and temperature cycling to demonstrate the performance and long term reliability and repeatability of the sensor.

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A High-Speed Temperature Sensor with Low Supply Sensitivity for SoC Thermal Monitoring

Journal of Circuits System and Computers ◽

10.1142/s0218126618501165 ◽

2018 ◽

Vol 27 (07) ◽

pp. 1850116

Author(s):

Yuanxin Bao ◽

Wenyuan Li

Keyword(s):

Temperature Sensor ◽

Conversion Rate ◽

High Speed ◽

Supply Voltage ◽

Ring Oscillator ◽

Temperature Sensitive ◽

Cmos Process ◽

Digital Code ◽

Thermal Monitoring ◽

Worst Case

A high-speed low-supply-sensitivity temperature sensor is presented for thermal monitoring of system on a chip (SoC). The proposed sensor transforms the temperature to complementary to absolute temperature (CTAT) frequency and then into digital code. A CTAT voltage reference supplies a temperature-sensitive ring oscillator, which enhances temperature sensitivity and conversion rate. To reduce the supply sensitivity, an operational amplifier with a unity gain for power supply is proposed. A frequency-to-digital converter with piecewise linear fitting is used to convert the frequency into the digital code corresponding to temperature and correct nonlinearity. These additional characteristics are distinct from the conventional oscillator-based temperature sensors. The sensor is fabricated in a 180[Formula: see text]nm CMOS process and occupies a small area of 0.048[Formula: see text]mm2 excluding bondpads. After a one-point calibration, the sensor achieves an inaccuracy of [Formula: see text][Formula: see text]1.5[Formula: see text]C from [Formula: see text]45[Formula: see text]C to 85[Formula: see text]C under a supply voltage of 1.4–2.4[Formula: see text]V showing a worst-case supply sensitivity of 0.5[Formula: see text]C/V. The sensor maintains a high conversion rate of 45[Formula: see text]KS/s with a fine resolution of 0.25[Formula: see text]C/LSB, which is suitable for SoC thermal monitoring. Under a supply voltage of 1.8[Formula: see text]V, the maximum energy consumption per conversion is only 7.8[Formula: see text]nJ at [Formula: see text]45[Formula: see text]C.

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Genetic analysis of temperature-sensitive lethal mutants of Salmonella typhimurium.

Genetics ◽

10.1093/genetics/123.4.625 ◽

1989 ◽

Vol 123 (4) ◽

pp. 625-633 ◽

Cited By ~ 1

Author(s):

M B Schmid ◽

N Kapur ◽

D R Isaacson ◽

P Lindroos ◽

C Sharpe

Keyword(s):

High Temperature ◽

Genetic Analysis ◽

Salmonella Typhimurium ◽

Complex Medium ◽

Temperature Sensitive ◽

Nonpermissive Temperature ◽

Anaerobic Conditions ◽

Temperature Growth ◽

Lethal Phenotype ◽

Lethal Mutations

Abstract We have isolated 440 mutants of Salmonella typhimurium that show temperature-sensitive growth on complex medium at 44 degrees. Approximately 16% of the mutations in these strains have been mapped to 17 chromosomal locations; two of these chromosomal locations seem to include several essential genes. Genetic analysis of the mutations suggests that the collection saturates the genes readily mutable to a ts lethal phenotype in S. typhimurium. Physiological characteristics of the ts lethal mutants were tested: 6% of the mutants can grow at high temperature under anaerobic conditions, 17% can grow when the medium includes 0.5 M KCl, and 9% of the mutants die after a 2-hr incubation at the nonpermissive temperature. Most ts lethal mutations in this collection probably affect genes required for growth at all temperatures (not merely during high temperature growth) since Tn10 insertions that cause a temperature-sensitive lethal phenotype are rare.

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Calcium Bismuth Titanate with High Curie Temperature (Tc) for High-Temperature Sensor Applications

Journal of Electronic Materials ◽

10.1007/s11664-021-09029-w ◽

2021 ◽

Author(s):

P. Sivagnanapalani ◽

Naveed Iqbal Ansari ◽

P. K. Panda

Keyword(s):

High Temperature ◽

Curie Temperature ◽

Temperature Sensor ◽

Bismuth Titanate ◽

High Curie Temperature ◽

Sensor Applications ◽

High Temperature Sensor ◽

Curie Temperature Tc

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Novel Multilayer SAW Temperature Sensor for Ultra-High Temperature Environments

Micromachines ◽

10.3390/mi12060643 ◽

2021 ◽

Vol 12 (6) ◽

pp. 643

Author(s):

Xuhang Zhou ◽

Qiulin Tan ◽

Xiaorui Liang ◽

Baimao Lin ◽

Tao Guo ◽

...

Keyword(s):

High Temperature ◽

Temperature Sensor ◽

X Ray Diffraction ◽

Aero Engine ◽

Before And After ◽

Application Potential ◽

Passive Sensors ◽

Temperature Exposure ◽

Engine Systems

Performing high-temperature measurements on the rotating parts of aero-engine systems requires wireless passive sensors. Surface acoustic wave (SAW) sensors can measure high temperatures wirelessly, making them ideal for extreme situations where wired sensors are not applicable. This study reports a new SAW temperature sensor based on a langasite (LGS) substrate that can perform measurements in environments with temperatures as high as 1300 °C. The Pt electrode and LGS substrate were protected by an AlN passivation layer deposited via a pulsed laser, thereby improving the crystallization quality of the Pt film, with the function and stability of the SAW device guaranteed at 1100 °C. The linear relationship between the resonant frequency and temperature is verified by various high-temperature radio-frequency (RF) tests. Changes in sample microstructure before and after high-temperature exposure are analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The analysis confirms that the proposed AlN/Pt/Cr thin-film electrode has great application potential in high-temperature SAW sensors.

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