The FSA8039A is an audio jack switch for a normally open detect pin. The FSA8039A can work with 3-pole and 4-pole accessories. The FSA8039A features moisture sensing, which prevents false positive detection of accessories in the audio jack. The integrated MIC switch allows a processor to configure attached accessories. The architecture is designed to allow common third-party headphones to be used for listening to music from mobile handsets, personal media players, and portable peripheral devices.