CONDENSER MICROPHONE EMPLOYING WIDE BAND STOP FILTER AND HAVING IMPROVED RESISTANCE TO ELECTROSTATIC DISCHARGE

摘要

A condenser microphone employs a wide band stop filter, having improved resistance to electrostatic discharge. This includes providing a condenser microphone used for a multi-band by comprising a wide band stop filter capable of efficiently blocking a wide band signal including low frequency and radio frequency used in a mobile communication. A condenser microphone includes: an acoustic module for converting sound pressure into an electric signal; an FET for amplifying the electric signal; and a wide band stop filter for blocking a wide band signal including low frequency and radio frequency output from the FET. The filter is realized by resistors and/or capacitors which are connected selectively according to the radio frequency band between the drain and the source of the FET. The range capable of removing EM noise is widened, an excellent filtering effect of noise is obtained, and resistance of electrostatic discharge applied from outside is improved.