RECENT ADVANCES ON MEASUREMENT OF SMALL CAPACITANCE OF MEMS CAPACITANCE DIAPHRAGM GAUGES

The miniaturization and overall performance of the MEMS capacitance diaphragm vacuum gauges is closely related to the small capacitance measurement circuit.Due to the application requirements in different fields，the MEMS capacitance diaphragm vacuum gauges have different sensitive capacitance structures while the corresponding small capacitance measurement methods are also different.The structure of small capacitance measurement circuit for one-side electrode is simple and the circuit is easy to implement.The structure of small capacitance measurement circuit for two-side electrode is complex，but the circuit can reduce the influence of parasitic capacitance and temperature to obtain high resolution.In addition，the small capacitance measurement method for force balance type structure uses closed loop circuit，this method can realize high precision and expand the dynamic range of vacuum gauges at the same time.It can be seen from the above that the high-precision，low power consumed and easily integrated small capacitance measurement circuit that can be applied to various types of MEMS capacitance sensors is of great significance for the future application of MEMS sensors from the aerospace and other sophisticated fields to the fields of artificial intelligence and the Internet of Things.