Method for adaptively tracking bias voltage and microphone device

Abstract

The invention discloses a method for adaptively tracking a bias voltage and a microphone device. The microphone device comprises an acoustic sensor. The acoustic sensor comprises a backplate and acoustic diaphragm formed on the backplate. The method for adaptively tracking the bias voltage comprises the following steps of S1, applying a continuously boosted bias voltage to the acoustic diaphragm,wherein when the bias voltage reaches a first set voltage, the sensitivity of a silica-based micro-electro-mechanical system microphone is reduced, and the first set voltage is recorded as a first voltage; S2, powering off and resetting the acoustic diaphragm; and S3, resetting the bias voltage, wherein the bias voltage is 60% to 80% of the first voltage. The technical scheme provided by the invention has the beneficial effects that the method for adaptively tracking the bias voltage and the microphone device are disclosed, a structure size of an instrument can be precisely controlled, the realization operation is simple, the bias voltage can be adaptively and dynamically changed, the sensitivity is improved, a signal to noise ratio is reduced, and the consistency of the performance is improved.

Description

technical field [0001] The invention relates to the field of silicon-based micro-electromechanical technology, in particular to a method for adaptively tracking a bias voltage and a microphone device. Background technique [0002] Acoustic sensors convert acoustic signals into electrical signals for various applications. Acoustic sensors have been widely used in a variety of electronic products, such as mobile phones, cameras, notebook computers, and microphones. In the prior art, according to different working principles, acoustic sensors can be classified into piezoelectric, piezoresistive and capacitive. [0003] At present, the acoustic sensor is composed of an acoustic diaphragm and a back plate to form a parallel plate capacitor. Under the action of sound pressure, the acoustic diaphragm will move to the back plate, and the capacitance value between the two plates will change, so that the acoustic signal will flow to the back plate. Conversion of electrical signals. ...

AI Technical Summary

Problems solved by technology

However, in mass production, the height, thickness, and lateral stress of the back plate structure will affect the sensitivity of the structure, and the concentration of hydrofluoric acid cannot be controlled during wet etching. Traditional calibration can only change the gain, which in turn At the cost of loss of performance, the signal-to-noise ratio is affected, that is, the concentration of hydrofluoric acid that corrodes the acoustic diaphragm in the prior art is not well controlled, and an acoustic sensor with good consistency cannot be obtained

Images