(1) Compatibility problem, caused a lot of trouble
Although the 3.5MM Plug Audio Connector has been designed in a consistent way, the 3.5mm Plug Audio Connector has different "factions" of design inside the 3.5MM connector, which makes the 3.5MM Plug Audio Connector
There are some issues with headphone compatibility.
The compatibility issues are mainly caused by different definitions of the 3.5mm TRRS interface specification.
At present, two kinds of mobile phone 3.5mm interface design standards are used internationally
One is OMTP and the other is CTIA. OMTP is our adopted standard and CTIA is the international standard.
So next, we have to figure out what the differences are between the OMTP and the CTIA standards in order to explain what problems these two design differences can cause.
Today's smart phones all support wire-controlled microphones. The following is the definition of TRRS terminals for analysis.
The above is a standard 3.5mm TRRS headphone. Notice the three black rings around the silver metal bar? They are insulation rings, and three insulation rings divide this metal bar into four parts. They are L segment, V segment, G segment, R segment.
In the national standard OMTP, the L segment is the left channel, the V segment is the right channel, the G segment is grounded, and the R segment is Microphone;
In the international standard CTLA, the L segment is the left channel, the V segment is the right channel, the G segment is connected to the Mic (Microphone), and the R segment is grounded.
