Issues in path toward integrated acoustic sensor system on chip

Size and power minimization requirements from portable consumer applications are driving integration of MEMS sensors with integrated circuits. For performance maximization, designers require MEMS device models MEMS that can be co-simulation with interface circuits for system optimization. Efficient simulation of both mechanical and electrical characteristics simultaneously is required for optimal design and to enable the design of more complex systems. In this paper, we use a co-simulation platform to design acoustic sensor system. A Verilog-A hardware description language model of a condenser MEMS microphone structure is co-simulated with interface circuits for optimal co-design. Measured result of the acoustic system achieved 69 dB SNR and -35 dBV/Pa sensitivity using 26 muW power. A sigma-delta modulator to transfer sound pressure wave to digital signal has been subsequently designed using this co-simulation platform. Simulation predicts an acoustic sensor system SNDR of 58 dB when the input signal is 10 kHz/1 Pa, and power consumption of 6.7 mW with a 3 V power supply.