A schematic-based design model for microphone and circuit integration

The transistor-level elements for condenser microphone design have been implemented in an IC design environment. Arbitrary diaphragm shapes can be composed and simulated by using our basic elements. The sensitivity and frequency response are obtained by co-simulation with the microphone and the readout circuit using Cadence/Spectre^reg simulator. The new model is capable of dealing with the multi-field coupling effects including acoustical, mechanical and electrostatic behavior. Comparing to the ANSYS static simulation by using shell63 elements, our design model gives matched results based on the same mesh condition. Both the finite element analysis and theoretical calculated natural frequency agree with the nodal simulation results. Co-simulation enables trade-off analysis between the acousto-electro-mechanical and electronic design parameters. Furthermore, this platform provides a unified design interface between mechanical and electrical engineers, which is critical for top-down design of monolithic microsystems.