【回転】Androidシステム3.5 mmイヤホンソケット説明
【声明】
本稿は『3.5 mm Headset Jack:Device Specification』から
【本文】
3.5 mm Headset Jack: Device Specification
To achieve compatibility with the 3.5 mm plug headset specification, devices that include a 4 conductor 3.5 mm audio jack must meet the following specifications. For Android compatibility requirements, refer to the Analog audio ports section of the Android CDD.
Functions
Function
Device Support
Stereo Audio Out
Required
Audio in (Mic)
Required
Ground
Required
Software mapping
Function
Device Support
Description
Function A control event
Required
Input event:
本稿は『3.5 mm Headset Jack:Device Specification』から
【本文】
3.5 mm Headset Jack: Device Specification
To achieve compatibility with the 3.5 mm plug headset specification, devices that include a 4 conductor 3.5 mm audio jack must meet the following specifications. For Android compatibility requirements, refer to the Analog audio ports section of the Android CDD.
Functions
Function
Device Support
Stereo Audio Out
Required
Audio in (Mic)
Required
Ground
Required
Software mapping
Function
Device Support
Description
Function A control event
Required
Input event:
KEY_MEDIA Android key: KEYCODE_HEADSETHOOK
Function D control event
Required
Input event: KEY_VOICECOMMAND Android key: KEYCODE_VOICE_ASSIST
Function B control event
Required
Input event: KEY_VOLUMEUP Android key: VOLUME_UP
Function C control event
Required
Input event: KEY_VOLUMEDOWN Android key: VOLUME_DOWN
Headset insertion detection
Required
Input event: SW_JACK_PHYSICAL_INSERT 7
Headset type detection
Mic
Input event: SW_MICROPHONE_INSERT 4
No Mic
Input event: SW_HEADPHONE_INSERT 2
Headset speaker impedance
Required Headphone (low)
Failure mode is to indicate headphones so limitation would be on
Required Line In (high)
Input event: SW_LINEOUT_INSERT 6
Mechanical
Function
Device Support
Description
4 conductor 3.5 mm jack
Required
CTIA pinout order (LRGM)
Required
3 Pin & Mono Plug Compatible
OMTP pinout order (LRMG)
Optional but strongly recommended
Headset detect sequence
Required
Plug insert notification must be triggered only after all contacts on plug are touching their relevant segments (this prevents unreliable headset detection due to slow insertion.
Electrical
General
Function
Device Support
Notes
Maximum output voltage drive
150mV
>= 150mV on 32 ohm Test conditions: EN50332-2
Mic bias resistance
Required
Flexible on detection method used and microphone bias resistor selection. Require that all button resistance value ranges specified below be detected and related to their respective function
Mic bias voltage
1.8V - 2.9V
To guarantee compatibility to common microphone capsules.
Function impedance and threshold detection
Devices must detect the following resistor ladder on the accessories. The accessories will be tested to the standardized circuit diagram in the diagram illustrated earlier (Reference Headset Test Circuit) where the total impedance is measured from MIC terminal to GND when a button is pressed with 2.2V mic bias applied through 2.2 kOhm resistor. This is the same effective resistance as the button detection circuit with the microphone in parallel with the button resistor.
Button Impedance Level
Device Support
Notes
70 ohm or less
Required
[Function A]
110 - 180 ohm
Required
[Function D]
210 - 290 ohm
Required
[Function B]
360 - 680 ohm
Required
[Function C]
Headset Speaker Impedance Level
Device Support
Notes
Low Threshold Detection
Required
Headphone (low) < 1 Kohm
High Threshold Detection
Required
Line In (high) > 5 Kohm
4-Segment Plug Detection Resistance (between 3rd and 4th segment)
Device Support
Notes
4-Segment Plug Threshold
Required
Resistance >= 100 ohms
3-Segment Plug Threshold
Required
Resistance < 100 ohms