As shown on this slide, audio headsets have three conductor or four conductor connectors, depending on whether they have a built-in microphone or not. Among the four conductor connectors, there are two competing standards having different configurations with the ground and mic rings reversed as shown. TI offers two audio jack switches, the TS3A26746E and TS3A225E that allow the system designer to support all of the headset configurations shown. The TS3A225E performs detection of the headset type, in addition to switching the ground and mic rings from the connector to the appropriate system signals. The TS3A26746E provides only the capability to switch the ground and mic signals, which means the headset type detection is to be performed elsewhere, in an audio codec, an audio amp, or a PMU. The result of this is that any headset can be used with a customer’s mobile device that contains these TI switches.