Article ID: 007020012 Last Update: 2022-08-24
Applies to: USB Fusion
Check whether your headphone uses the CTIA standard. The headset port uses the CTIA standard, so when an OMTP-compliant headphone connects to the port, there will be some anomaly. In this case, you need to connect your headphone through an OMTP-to-CTIA converter.
At present, there are two international standards for handset headphone jacks: OMTP and CTIA. In general, most international manufacturers use CTIA standards, such as iPhone headsets in the United States and other international markets, while mobile phone headsets in some other markets need to support the OMTP standard.
Pinout order of CTIA standard: left audio - right audio - ground - microphone.
Pinout order of OMTP standard: left audio - right audio - microphone - ground.