Fairchild Semiconductor Enables Detection of Different Audio Accessories with a Single Device

Fairchild Semiconductor developed the FSA8008 audio jack detection and configuration switch as a one-chip audio jack detector and switch for 3- or 4-pole accessories. While current solutions use several discrete components (dual comparator, analogue switch and MOSFET) with software control to meet this need, the FSA8008 integrates this functionality into a single device, simplifying designs, and saving up to 70 percent of the board space and up to 15 percent bill of material (BOM) costs.



In addition to detection, the FSA8008 is designed to allow common, third party headphones to be used for listening to music, which is made possible due to an integrated microphone (MIC) switch that allows the processor to configure the audio jack. The FSA8008 also eliminates leakage current when the MIC is plugged into the jack.



Another key feature of this device is the ability to eliminate the insertion pop and click noise on the MIC path when the jack touches the MIC bias first. Additionally, the FSA8008 eliminates the software work-around needed when the send/end key is pressed or stuck.



The device features 15kV (air gap) and 12kV (HBM) ESD protection, as well as 0.01 percent (typical) total harmonic distortion (MIC). The FSA8008 is available in a 10-lead UMLP package (1.4 x 1.8 x 0.5mm, 0.4mm pitch).



Fairchild Semiconductor enables engineers to differentiate their designs by identifying market trends and developing solutions to meet those needs. The FSA8008 leverages Fairchild’s expertise in the development of solutions that advance mobile designs and enrich the end-user experience.