Department of Mechanical Engineering, National Taiwan University, Taipei, 106, Taiwan.
Sensors (Basel). 2011;11(11):10308-25. doi: 10.3390/s111110308. Epub 2011 Oct 31.
This paper presents a novel CMOS wireless temperature sensor design in order to improve the sensitivity and linearity of our previous work on such devices. Based on the principle of CMOS double zero temperature coefficient (DZTC) points, a combined device is first created at the chip level with two voltage references, one current reference, and one temperature sensor. It was successfully fabricated using the 0.35 μm CMOS process. According to the chip results in a wide temperature range from -20 °C to 120 °C, two voltage references can provide temperature-stable outputs of 823 mV and 1,265 mV with maximum deviations of 0.2 mV and 8.9 mV, respectively. The result for the current reference gives a measurement of 23.5 μA, with a maximum deviation of 1.2 μA. The measurements also show that the wireless temperature sensor has good sensitivity of 9.55 mV/°C and high linearity of 97%. The proposed temperature sensor has 4.15-times better sensitivity than the previous design. Moreover, to facilitate temperature data collection, standard wireless data transmission is chosen; therefore, an 8-bit successive-approximation-register (SAR) analog-to-digital converter (ADC) and a 433 MHz wireless transmitter are also integrated in this chip. Sensing data from different places can be collected remotely avoiding the need for complex wire lines.
本文提出了一种新颖的 CMOS 无线温度传感器设计，以提高我们之前在该类设备上工作的灵敏度和线性度。基于 CMOS 双零温度系数（DZTC）点的原理，首次在芯片级创建了一个组合器件，其中包括两个电压基准、一个电流基准和一个温度传感器。它是使用 0.35μm CMOS 工艺成功制造的。根据芯片在-20°C 至 120°C 的宽温度范围内的结果，两个电压基准可以提供温度稳定的输出，分别为 823 mV 和 1,265 mV，最大偏差为 0.2 mV 和 8.9 mV。电流基准的测量结果为 23.5 μA，最大偏差为 1.2 μA。测量结果还表明，无线温度传感器具有 9.55 mV/°C 的良好灵敏度和 97%的高线性度。与之前的设计相比，所提出的温度传感器的灵敏度提高了 4.15 倍。此外，为了方便温度数据采集，选择了标准的无线数据传输；因此，该芯片还集成了一个 8 位逐次逼近寄存器（SAR）模数转换器（ADC）和一个 433 MHz 无线发射器。可以远程采集来自不同地方的感应数据，避免了复杂的电线。
