[K-2] Advanced Sensor Systems

[K-2-01] High-Resolution Sensor Interface IC with Switched-Capacitor Frequency Locked Loop Circuit for Battery-less RF Backscatter Sensing

〇Hiroki Sato¹, Hiroyuki Ishiwata², Shinji Murata², Noboru Ishihara³, Hiroyuki Ito³ (1. Nisshinbo Micro Devices Inc. (Japan), 2. ALPS ALPINE Corp., Ltd. (Japan), 3. Tokyo Inst. of Tech. (Japan))

Presentation style: On-site (in-person)

https://doi.org/10.7567/SSDM.2022.K-2-01

A sensor interface IC that enables battery-less wireless sensing is proposed. The circuit consists of a sensor interface circuit with an instrumentation amplifier and a frequency locked loop FLL for highly sensitive and stable operation, an RF backscatter circuit that enables wireless sensing without power consumption, and an energy harvester circuit that enables battery less operation was integrated by the 0.13-μm CMOS process technology. As a result of inputting a 920MHz RF signal to the IC, we succeeded in realizing wireless sensing by intermittent operation without batteries. The sensor information could be obtained by the frequency variation of the RF backscatter signal, and the sensitivity to the sensor voltage was 12kHz/mV. The IC operated with an RF signal power input of more than -5dBm. The IC dissipate less than 150μA.
The IC is expected to be applied to such as internal body monitoring for medical use and monitoring of blind environments such as in luggage and structures.