MEMS MICROPHONE
To generate a differential signal whose phase is inverted while suppressing increase of circuit scale of a MEMS microphone.SOLUTION: A MEMS microphone includes: a diaphragm having conductivity; a first variable capacitor having a first fixed electrode facing to the diaphragm, whose capacitance chang...
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Main Authors | , , , , , |
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Format | Patent |
Language | English Japanese |
Published |
05.10.2023
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Subjects | |
Online Access | Get full text |
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Summary: | To generate a differential signal whose phase is inverted while suppressing increase of circuit scale of a MEMS microphone.SOLUTION: A MEMS microphone includes: a diaphragm having conductivity; a first variable capacitor having a first fixed electrode facing to the diaphragm, whose capacitance changes according to vibration of the diaphragm; a second variable capacitor having a second fixed electrode facing to the diaphragm, whose capacitance changes according to vibration of the diaphragm; a first voltage output part for outputting a first voltage changes according to the change of the capacitance of the first variable capacitor; and a second voltage output part for outputting a second voltage changes according to the change of the capacitance of the second variable capacitor, a first bias voltage is applied to the first fixed electrode, a reference voltage is applied to the second fixed electrode, and a second bias voltage whose difference from the reference voltage is half of the difference between the first bias voltage and the reference voltage is applied to the diaphragm.SELECTED DRAWING: Figure 1
【課題】MEMSマイクロフォンの回路規模の増大を抑制しつつ、位相が反転された差動信号を生成する。【解決手段】MEMSマイクロフォンは、導電性を有する振動膜と、振動膜に対向する第1固定電極を有し、振動膜の振動に応じて静電容量が変化する第1可変キャパシタと、振動膜に対向する第2固定電極を有し、振動膜の振動に応じて静電容量が変化する第2可変キャパシタと、第1可変キャパシタの静電容量の変化に応じて変化する第1電圧を出力する第1電圧出力部と、第2可変キャパシタの静電容量の変化に応じて変化する第2電圧を出力する第2電圧出力部と、を有し、第1固定電極には、第1バイアス電圧が印加され、第2固定電極には、基準電圧が印加され、振動膜には、基準電圧との差が、第1バイアス電圧と基準電圧との差の半分である第2バイアス電圧が印加される。【選択図】図1 |
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Bibliography: | Application Number: JP20220049224 |