Resonant-Based Capacitive Pressure Sensor Read-Out Oscillating at 1.67 GHz in 0.18

This paper presents a resonant-based read-out circuit for capacitive pressure sensors. The proposed read-out circuit consists of an LC oscillator and a counter. The circuit detects the capacitance changes of a capacitive pressure sensor by means of frequency shifts from its nominal operation frequency. The proposed circuit is designed in 0.18μm CMOS with an estimated power consumption of 43.1mW. Simulation results show that the circuit has a capacitive resolution of 8.06kHz/fF, which enables it for high resolution pressure detection. Keywords—Capacitance-to-frequency converter, Capacitive pressure sensor, Digital counter, LC oscillator.