Counter-Based Frequency Discriminator for Fine Dust Sensor

Abstract

This work presents a counter-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 and low power of 0.3 mW, which facilitates the integration into portable devices. The proposed counter-based frequency discriminator covers the input frequency range of 1.6 to 2.4 GHz with a resolution of 50 kHz. Since it has a flexible divider, its resolution and detection speed can be flexibly changed.