A High-Temperature Piezoresistive Pressure Sensor with an Integrated Signal-Conditioning Circuit

The field of piezoresistive sensors has been undergoing a significant revolution in terms of design methodology, material technology and micromachining process. However, the temperature dependence of sensor characteristics remains a hurdle to cross. This review focuses on the issues in thermal-performance instability of piezoresistive sensors. Based on the operation fundamental, inducements to the instability are investigated in detail and correspondingly available ameliorative methods are presented. Pros and cons of each improvement approach are also summarized. Though several schemes have been proposed and put into reality with favorable achievements, the schemes featuring simple implementation and excellent compatibility with existing techniques are still emergently demanded to construct a piezoresistive sensor with excellent comprehensive performance.

Section: Improvement In Thermal-performance Stabilitymentioning

confidence: 99%

“…Until now, silicon piezoresistances have been utilized in the detection of various targets, including acceleration [4,5,6], pressure [7,8], micro force/torque [9,10], strain/stress [11,12], flow [13,14], biochemical interaction [15,16], fluid density and viscosity [17,18], surface topography [19], sonar vectors [20], etc.…”

Section: Introductionmentioning

confidence: 99%

Thermal-Performance Instability in Piezoresistive Sensors: Inducement and Improvement

Liu

Wang

Zhao

et al. 2016

“…The passive compensation techniques were also adopted to eliminate pressure sensor output voltage drop with the increase in temperature [ 8 , 10 , 11 ]. For a piezoresistive pressure sensor, a built-in passive temperature compensation technique is introduced in [ 9 ].…”

Section: Introductionmentioning

confidence: 99%

“…An extra polysilicon resistor with negative temperature coefficient of resistivity (TCR) is employed inside a sensor-fabricated patch instead of the calibration process. In [ 11 ], a similar passive resistor temperature compensation method is presented in which the system parameters are manipulated by using differential equations. These passive techniques reduce TCS but TCO is not eliminated.…”

Section: Introductionmentioning

confidence: 99%

A Highly Accurate, Polynomial-Based Digital Temperature Compensation for Piezoresistive Pressure Sensor in 180 nm CMOS Technology

Ali

Asif

Shehzad

et al. 2020

Recently, piezoresistive-type (PRT) pressure sensors have been gaining attention in variety of applications due to their simplicity, low cost, miniature size and ruggedness. The electrical behavior of a pressure sensor is highly dependent on the temperature gradient which seriously degrades its reliability and reduces measurement accuracy. In this paper, polynomial-based adaptive digital temperature compensation is presented for automotive piezoresistive pressure sensor applications. The non-linear temperature dependency of a pressure sensor is accurately compensated for by incorporating opposite characteristics of the pressure sensor as a function of temperature. The compensation polynomial is fully implemented in a digital system and a scaling technique is introduced to enhance its accuracy. The resource sharing technique is adopted for minimizing controller area and power consumption. The negative temperature coefficient (NTC) instead of proportional to absolute temperature (PTAT) or complementary to absolute temperature (CTAT) is used as the temperature-sensing element since it offers the best temperature characteristics for grade 0 ambient temperature operating range according to the automotive electronics council (AEC) test qualification ACE-Q100. The shared structure approach uses an existing analog signal conditioning path, composed of a programmable gain amplifier (PGA) and an analog-to-digital converter (ADC). For improving the accuracy over wide range of temperature, a high-resolution sigma-delta ADC is integrated. The measured temperature compensation accuracy is within ±0.068% with full scale when temperature varies from −40 °C to 150 °C according to ACE-Q100. It takes 37 µs to compute the temperature compensation with a clock frequency of 10 MHz. The proposed technique is integrated in an automotive pressure sensor signal conditioning chip using a 180 nm complementary metal–oxide–semiconductor (CMOS) process.

“…There is no measurement technology currently available to achieve direct, accurate measurements of static and dynamic pressure changes in extremely high temperature environments such as gas turbines, high-speed combustors, and other aerospace propulsion applications [ 1 ]. Conventional silicon pressure sensors and even silicon-on-insulator (SOI) sensors cannot operate at high temperatures over 500 °C due to the plastic deformation of the material [ 2 , 3 ]. In addition, some micromachined pressure sensors based on silicon carbide [ 4 , 5 , 6 ] and ceramic [ 7 , 8 ] have also been developed.…”

Section: Introductionmentioning

confidence: 99%

Interface Characteristics of Sapphire Direct Bonding for High-Temperature Applications

Liang

Chen

et al. 2017

Self Cite

In this letter, we present a sapphire direct bonding method using plasma surface activation, hydrophilic pre-bonding, and high temperature annealing. Through the combination of sapphire inductively coupled plasma etching and the direct bonding process, a vacuum-sealed cavity employable for high temperature applications is achieved. Cross-sectional scanning electron microscopy (SEM) research of the bonding interface indicates that the two sapphire pieces are well bonded and the cavity structure stays intact. Moreover, the tensile testing shows that the bonding strength of the bonding interface is in excess of 7.2 MPa. The advantage of sapphire direct bonding is that it is free from the various problems caused by the mismatch in the coefficients of thermal expansion between different materials. Therefore, the bonded vacuum-sealed cavity can be potentially further developed into an all-sapphire pressure sensor for high temperature applications.