Frequency discriminator for the fine dust sensor

Abstract

This work presents a delay-locked-loop (DLL)- based frequency discriminator for a fine dust sensor. Detecting the frequency variations of MEMS resonator according to the fine dust concentration, the proposed frequency discriminator provides digital codes which represents the frequency variations. Since the proposed frequency discriminator is based on the CMOS process, it achieved extremely small area of 0.18 mm2 and low power of 12 mW, which facilitates the integration into portable device. The proposed DLL-based frequency discriminator covers the input frequency range of 1890 to 2486 MHz with a resolution of 144 kHz, thus it can discriminate input frequencies with 4111 steps. Additionally, to increases the PVT robustness, it used KVCDL compensation technique.