A low-noise CMOS interface circuit for resonant pressure sensor

This paper presents a low-noise CMOS interface circuit of the resonant pressure sensor. A high-frequency carrier is employed to extract the small vibration signal of the resonator and suppress the low-frequency coupling signal. A differential detection circuit is implemented to suppress common mode noise. Sensor chip is packaged together with the interface ASIC, reducing the coupling capacitor of the resonator and the sensing electrode. The AS IC is fabricated in a 0.18 um CMOS process and the sensor chip is fabricated using a commercially available silicon-on-insulator wafer. The test result shows that the resonant pressure sensor has a nonlinearity of 0.045%FS, a hysteresis error of 0.14%FS, and a repeatability error of 0.18%FS.