Ali Imran, Asif Muhammad, Shehzad Khuram, Rehman Muhammad Riaz Ur, Kim Dong Gyu, Rikan Behnam Samadpoor, Pu YoungGun, Yoo Sang Sun, Lee Kang-Yoon
College of Information and Communication Engineering, Sungkyunkwan University (SKKU), Suwon 16419, Korea.
Sensors (Basel). 2020 Sep 14;20(18):5256. doi: 10.3390/s20185256.
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.
最近，压阻式（PRT）压力传感器因其结构简单、成本低、尺寸小巧且坚固耐用，在各种应用中受到了广泛关注。压力传感器的电学性能高度依赖于温度梯度，这严重降低了其可靠性并影响测量精度。本文提出了一种基于多项式的自适应数字温度补偿方法，用于汽车压阻式压力传感器应用。通过结合压力传感器随温度变化的相反特性，精确补偿了压力传感器的非线性温度依赖性。补偿多项式在数字系统中完全实现，并引入了一种缩放技术来提高其精度。采用资源共享技术以最小化控制器面积和功耗。使用负温度系数（NTC）而非与绝对温度成正比（PTAT）或与绝对温度互补（CTAT）作为温度传感元件，因为根据汽车电子协会（AEC）的测试认证ACE-Q100，在0级环境温度工作范围内，它具有最佳的温度特性。共享结构方法利用现有的模拟信号调理路径，该路径由可编程增益放大器（PGA）和模数转换器（ADC）组成。为了在宽温度范围内提高精度，集成了一个高分辨率的sigma-delta ADC。根据ACE-Q100标准，当温度在-40°C至150°C之间变化时，测量得到的温度补偿精度在满量程时为±0.068%。在10 MHz的时钟频率下，计算温度补偿需要37微秒。所提出的技术采用180纳米互补金属氧化物半导体（CMOS）工艺集成在汽车压力传感器信号调理芯片中。
