ABSTRACT
This chapter presents the basic knowledge of the interface circuits for capacitive microelectromechanical system (MEMS) gyroscopes, along with the principles of the gyroscopes, and the practical considerations of the non-idealities. Various non-idealities exist in real gyroscopes, and some of them may affect the performance of a gyroscope so significantly that they have to be considered during the electronics design. For the interface circuits without the dynamic cancellation technologies, the front-end circuitry needs to have large dynamic range to tolerate the signal amplitude due to the direct-coupled motions. Most of the commercially available MEMS gyroscopes for consumer electronics are based on the vibratory concept, in which case the rotary rate is detected through the so-called Coriolis Effect. The discrete-time read-out circuits sample the signal under certain frequency, which is usually much higher than the Coriolis signal, for further processing. The read-out circuits work to convert the capacitive change to electrical signals that can be further processed, such as voltage, current, frequency.
