Resistor-based Temperature Sensor Research Articles

A 0.9V Self-Referenced Resistor-Based Temperature Sensor With −0.62/+0.81°C (3σ) Inaccuracy

A 0.9V Self-Referenced Resistor-Based Temperature Sensor With −0.62/+0.81°C (3σ) Inaccuracy

A 0.9-V 6400-μm2 Resistor-Based Temperature Sensor With a One-Point Trimmed 3σ Inaccuracy of ±0.64 °C from −50°C to 125 °C

This paper describes a compact and precise resistive temperature sensor based on a frequency-locked loop (FLL) intended for thermal monitoring in system-on-chips. The FLL incorporates a switched-capacitor loop filter improving the sensors inaccuracy and FLL outputs are converted into a digital code with an edge-combined counter for efficient frequency-to-digital conversion. A prototype sensor is fabricated in 65-nm CMOS process and occupies only 6,400 μm2. It achieves a one-point trimmed 3σ inaccuracy of 10.64 ∘C over a wide temperature range of.50 to 125 ∘C. Operating at 0.9 V supply, it consumes 40 μW and achieves 2.2 mK resolution in a 1-ms conversion time, which corresponds to a resolution FoM of 0.19 pJ7K2.

A Multimodality Electrochemical and Impedance Spectroscopy System-on-a-Chip With Temperature Sensing and Impedance-Boosting Techniques.

This article presents a multimodal electrochemical sensing system-on-chip (SoC), including the functions of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and temperature sensing. CV readout circuitry achieves an adaptive readout current range of 145.5 dB through an automatic range adjustment and resolution scaling technique. EIS has an impedance resolution of 9.2 m Ω/√ Hz at a sweep frequency of 10 kHz and an output current of up to 120 μA. With an impedance boost mechanism, the maximum detectable load impedance is extended to 22.95 k Ω, while the total harmonic distortion is less than 1%. A resistor-based temperature sensor using a swing-boosted relaxation oscillator can achieve a resolution of 31 mK in 0-85 °C. The design is implemented in a 0.18 μm CMOS process. The total power consumption is 1 mW.

Tunnel Magnetoresistance Based Passive Resistance Replacement in Hybrid MTJ-CMOS Integration

Previous theoretical and experimental works revealed the novel factors that Magnetic tunnel junction (MTJ) can be integrated into novel hybrid circuits except for memory applications. This paper makes exploitation of tunnel magnetoresistacne based replacement in diminishing layout penalty of on-chip passive component during circuit design and takes sigma-delta analog-to-digital converter (SD-ADC), resistor-based temperature sensor (-55 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula> C <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\sim 125^{\circ }$</tex-math></inline-formula> C) as two case study where large resistance is needed and restricts the scaling down. Considering the application in MRAM, the mainstream field of MTJ process and dealing with the problems of MRAM in wide temperature write operation, two temperature adaptive write schemes of MRAM are also proposed as the further applications of the proposed MTJ-based temperature sensor. The research of these circuits covers major characteristics of MTJ as the passive component, including area, variation and temperature characteristics. Large CMOS resistance in SD-ADC and bridge transducer in resistor-based temperature sensor are replaced by MTJ-based resistors. Simulation results reveal that the layout area of passive resistors in resistor-capacitor (RC) integrator was greatly reduced by the tunnel magnetoresistacne based replacement, specifically by 94.52% in comparison with fully 28nm CMOS design or 94.13% for wide temperature use. As for other figures of merit (FoM), Effective Numbers of Bits (ENOB) is improved by 0.06 bit along with higher thermal stability, and Signal-to-Noise Ratio (SNR) is decreased by 1.1 dB as design trade-off. In addition, the MTJ based bridge transducer in resistor-based temperature sensor can reduce the resistance layout area by over 90% with better linearity comparing with general CMOS resistor-based temperature sensor designs. Based on the MTJ-based temperature sensor, the two different adaptive write circuits help reduce write power consumption and delay of MRAM respectively for wide temperature use.

A 6800-$\mu$ m2 Resistor-Based Temperature Sensor With ±0.35 °C (3$\sigma$ ) Inaccuracy in 180-nm CMOS

This paper describes a compact resistor-based temperature sensor that has been realized in a 180-nm CMOS process. It occupies only 6800 $\mu \text{m}^{2}$ , thanks to the use of a highly digital voltage-controlled oscillator (VCO)-based phase-domain sigma–delta modulator, whose loop filter consists of a compact digital counter. Despite its small size, the sensor achieves ±0.35 °C (3 $\sigma $ ) inaccuracy from −35 °C to 125 °C. Furthermore, it achieves 0.12 °C (1 $\sigma $ ) resolution at 2.8 kSa/s, which is mainly limited by the time-domain quantization imposed by the counter.

A 5800-$\mu$ m2 Resistor-Based Temperature Sensor With a One-Point Trimmed Inaccuracy of ±1.2 °C ($3\sigma$ ) From −50 °C to 105 °C in 65-nm CMOS

This letter describes a compact resistor-based temperature sensor intended for the thermal monitoring of microprocessors and DRAMs. It consists of an RC poly phase filter (PPF) that is read out by a frequency-locked loop (FLL) based on a dual zero-crossing (ZC) detection scheme. The sensor, fabricated in 65-nm CMOS, occupies 5800 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and achieves moderate accuracy [±1.2 °C (3σ)] over a wide temperature range (-50 °C to 105 °C) after a one-point trim. This is 2x better than the previous compact resistor-based sensors. Operating from 0.85 to 1.3-V supplies, it consumes 32.5-μA and achieves 2.8-mK resolution in a 1-ms conversion time, which corresponds to a resolution FoM of 0.26 pJ·K <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .

A High Accuracy and Low Power Temperature Sensor

A resistor-based temperature sensor is designed intended for the temperature compensation of MEMS frequency references. High resolution is then required critically to minimize jitter. A Wien bridge RC filter is used to realize the temperature sensor. When the RC filter is driven at the resonant frequency of the filter, the change of temperature results in phase shift. This phase shift is then digitized by a phase-domain sigma-delta modulator whose phase-summing node is realized by a chopper demodulator. Implemented in a 65nm CMOS technology, the maximum power consumption is only 0.096mW under a supply voltage of 1.2V, and achieves 345 μKrms resolution in a 5 ms conversion time. The sensor occupies an area of 1150μm × 650μm. It achieves ±0.035 inaccuracy over the industrial range (-40°C-85°C).

A 0.25 mm2-Resistor-Based Temperature Sensor With an Inaccuracy of 0.12 °C (3&lt;inline-formula&gt; &lt;tex-math notation="LaTeX"&gt;$\sigma$ &lt;/tex-math&gt; &lt;/inline-formula&gt;) From −55 °C to 125 °C

This paper describes a compact, energy efficient, resistor-based temperature sensor that can operate over a wide temperature range (−55 °C–125 °C). The sensor is based on a Wheatstone bridge (WhB) made from silicided poly-silicon and non-silicided poly-silicon resistors. To achieve both area and energy efficiencies, the current output of the WhB is digitized by a continuous-time zoom analog-to-digital converter (ADC). Implemented in a standard 180-nm CMOS technology, the sensor consumes 52 $\mu \text{A}$ from a 1.8-V supply and achieves a resolution of 280 $\mu \text{K}_{\mathbf {rms}}$ in a 5-ms conversion time. This corresponds to a state-of-the-art resolution figure-of-merit (FoM) of 40 fJ $\cdot ~\text{K}^{2}$ . After a first-order fit, the sensor achieves an inaccuracy of ±0.12 °C (3 $\sigma $ ) from −55 °C to 125 °C.

An Annular Mechanical Temperature Compensation Structure for Gas-Sealed Capacitive Pressure Sensor

A novel gas-sealed capacitive pressure sensor with a temperature compensation structure is reported. The pressure sensor is sealed by Au-Au diffusion bonding under a nitrogen ambient with a pressure of 100 kPa and integrated with a platinum resistor-based temperature sensor for human activity monitoring applications. The capacitance-pressure and capacitance-temperature characteristics of the gas-sealed capacitive pressure sensor without temperature compensation structure are calculated. It is found by simulation that a ring-shaped structure on the diaphragm of the pressure sensor can mechanically suppress the thermal expansion effect of the sealed gas in the cavity. Pressure sensors without/with temperature compensation structures are fabricated and measured. Through measured results, it is verified that the calculation model is accurate. Using the compensation structures with a 900 μm inner radius, the measured temperature coefficient is much reduced as compared to that of the pressure sensor without compensation. The sensitivities of the pressure sensor before and after compensation are almost the same in the pressure range from 80 kPa to 100 kPa.