Humidity-to-Frequency Sensor in CMOS Technology With Wireless Readout
Humidity-to-Frequency Sensor in CMOS Technology With Wireless Readout
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DOI：
10.1109/jsen.2012.2217376
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发表时间：
2013-03-01
影响因子：
4.3
通讯作者：
Donaldson, Nick
中科院分区：
文献类型：
--
作者：
Cirmirakis, Dominik;Demosthenous, Andreas;Donaldson, Nick
介绍了一种用于湿度测量的远程供电微系统。有源应答器的核心由一个采用标准互补金属氧化物半导体（CMOS）技术制造的湿度频率转换芯片组成，该芯片包含湿度传感器和读出电路。该传感器采用聚酰亚胺钝化层和所用技术中可用的顶部金属层构建。电源和数据传输，从芯片，分别使用同一对电感耦合线圈与13.56 MHz的载波。湿度读数通过负载移位键控传输到外部电路。该芯片是用商业0.6 μ m CMOS技术制造的，占地面积为4.8 mm（2）。该传感器的电容表现出良好的线性相对湿度（RH）水平从15%到85%。在35 ℃时，标准化灵敏度为0.073%/ %RH.电路级校准将工艺和失配变化的扩展限制在约10%。该芯片的总功耗为1.39 mW。该装置有两个目的;或者作为独立的无线湿度传感器，或者用于评估包装的气密性，例如在生物医学植入物中。
A remotely powered microsystem for humidity measurement is presented. The core of the active transponder consists of a humidity-to-frequency chip fabricated in a standard complementary metal-oxide-semiconductor (CMOS) technology, which contains both the humidity sensor and the readout circuit. The sensor is constructed using the polyimide passivation layer and the top metal layer available in the technology used. Power and data transmissions, to and from the chip, respectively, use the same pair of inductively coupled coils with a 13.56 MHz carrier. The humidity readout is transmitted by load shift keying to the external circuit. The chip is fabricated with commercial 0.6-mu m CMOS technology and occupies an area of 4.8 mm(2). The sensor's capacitance exhibited good linearity against relative humidity (RH) levels from 15% to 85%. The normalized sensitivity is 0.073% per %RH at 35 C. The circuit level calibration limited spread from process and mismatch variations to about 10%. The chip has a total power consumption of 1.39 mW. The device has two purposes; either as a stand-alone wireless humidity sensor or to evaluate the hermeticity of packages, such as in biomedical implants.