Analog-CMDA based interfaces for MEMS gyroscopes
This work moves toward the state-of-the-art for the interfaces usually employed for three-axes micromachined gyroscopes. Several architectures based on multiplexing schemes in order to extremely simplify the analog front-end which can be based on a single charge amplifier are analyzed and compared. This paper presents a novel solution that experiments an innovative readout technique based on a special analog-CDMA (Code Division Multiplexing Access); this architecture can reach a considerable reduction of the analog front-end with reference to other multiplexing schemes. Many family codes have been considered in order to find the best trade-off between performance and complexity. System-level simulations prove the effectiveness of this technique in processing all the required signals. Finally, a case study is analyzed: a comparison with the SD740 micro-machined integrated inertial module with a tri-axial gyroscope by SensorDynamics AG is provided.
mems analog front-end cdma capacitive gyroscope mixed-signal readout interfaces walsh codes