A 0.25mm² AC-biased MEMS microphone interface with 58dBA SNR

Abstract

Capacitive MEMS microphone roadmaps are mainly driven by increasing SNR and reducing size/cost. This requires smaller microphones, ASICs with lower noise and smaller area, and cheaper packaging. Because of fundamental limitations, traditional DC-biased microphones will have difficulty following these trends. This paper proposes an AC-biasing scheme, which leads to a significant reduction in ASIC size and module packaging cost.