MEMS microphone using noise filter
US8983090B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 2013 |
| Grant date | Mar 17, 2015 |
| Priority date | — |
| Expiry date | Apr 7, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2410/03
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An MEMS microphone is provided which includes a reference voltage/current generator configured to generate a DC reference voltage and a reference current; a first noise filter configured to remove a noise of the DC reference voltage; a voltage booster configured to generate a sensor bias voltage using the DC reference voltage the noise of which is removed; a microphone sensor configured to receive the sensor bias voltage and to generate an output value based on a variation in a sound pressure; a bias circuit configured to receive the reference current to generate a bias voltage; and a signal amplification unit configured to receive the bias voltage and the output value of the microphone sensor to amplify the output value. The first noise filter comprises an impedance circuit; a capacitor circuit connected to a output node of the impedance circuit; and a switch connected to both ends of the impedance circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.