High Power-Efficiency Readout Circuit for MEMS Capacitive Accelerometer

MEMS capacitive accelerometers play a fundamental role in a wide range of monitoring systems for the Internet of Things (IoT) applications. In these applications, sensors are powered by battery, therefore high power-efficiency is required to extend battery life. To promote high efficiency design technique, the innovation on the readout circuit is of significance. In recent years, there has been growing interest in developing high power-efficiency readout circuit with specific performances, such as low power consumption and compact area required by wearable devices, low noise floor required by industrial instrument and high bandwidth required by vibration monitoring. The force feedback structure, the voltage-controlled structure and the charge-balanced structure are three important structures for the readout circuit to meet these performance requirements. This brief presents the important progresses of these three readout structures in recent years and summarizes the development trends in the future.