Double backplate MEMS microphone with a single-ended amplifier input port

摘要

A double backplate microphone having a good signal-to-noise ratio and being produceable at reduced manufacturing costs is provided. A microphone comprises a first backplate BP1, a second backplate BP2 and a membrane M. The microphone further comprises an amplifier AMP with a single-ended input port. The first backplate BP1 is electrically connected to the single-ended input port.

主权项

1. A double backplate microphone, comprising
a micro-electro-mechanical system (MEMS) chip, an amplifier with an single-ended input port, a first backplate, electrically connected to the single-ended input port, a second backplate electrically connected to ground, a membrane, arranged between the first and the second backplate, a first resistive element having a resistance >=1 GΩ and electrically connected to the first backplate, a second resistive element having a resistance >=1 GΩ and electrically connected to the membrane, a first capacitance C1 between the first backplate and the membrane, a second capacitance C2 between the second backplate and the membrane, a parasitic capacitance Cp1 between the first backplate and ground, a parasitic capacitance Cm between the membrane and ground, a parasitic capacitance CP2 between the second backplate and ground, where 4 pF<=Cm=C1=C2<=8 pF, Cp1=0.1*C1, Cp2=0.5*C1, the first backplate, the membrane, and the second backplate are arranged on the MEMS-chip.