INTERFACE FOR MEMS INERTIAL SENSORS

摘要

A high-performance interface circuit for micro-electromechanical (MEMS) inertial sensors is described. In accordance with one aspect, an excitation signal (used to detect capacitance variation) is used to control the value of an actuation signal bit stream to allow the dynamic range of both actuation and detection paths to be maximized and to prevent folding of high frequency components of the actuation bit stream due to mixing with the excitation signal. In another aspect, the effects of coupling between actuation signals and detection signals may be overcome by performing a disable/reset of at least one of and preferably both of the detection circuitry and the MEMS detection electrodes during actuation signal transitions. In a still further aspect, to get a demodulated signal to have a low DC component phase adjustment of sense and drive bit streams is applied.