Apparatus and method to provide advanced microphone bias
US7978863B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 26, 2006 |
| Grant date | Jul 12, 2011 |
| Priority date | — |
| Expiry date | Oct 28, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R3/00
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A circuit includes a differential amplifier having a first input for coupling to a first terminal of a microphone and a second input for coupling to a first terminal of a component having an impedance value that is substantially equal to an impedance value of the microphone, where a second terminal of the microphone and a second terminal of the component are coupled to circuit ground. The circuit further includes a first resistance having a first node coupled to a source of microphone bias voltage and a second node coupled to the first terminal of the microphone; and a second resistance having a first node coupled to the source of microphone bias voltage and a second node coupled to the first terminal of the component. Operation of the differential amplifier results in attenuating or suppressing common mode noise and interference present in the microphone bias voltage and in the common potential.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.