Question of the TLV320AIC3106 Mic Bias

Hello Luis,

Addition, Did you mean that we need to change R396 to 0ohm to bypass this net for MICDET? 
If we change R396 to 0ohm, Can our original circuit's MICDET functional (Option 1)?

With this option, we got headset compatibility problem:

1. Apple headset(3.5mm jack): we got “00 no headset detected”.
2. HTC headset(3.5mm jack): we got “01 headset without microphone detected”.
3. ASUS headset(3.5mm jack): we got “11 headset with microphone detected”.


 
Can we solve this problem to the configuration below (option 2)?


 Thank you and Best regards,

Wayne Chen
08/25/2016

Hello Luis,

The AIC3106's hook button detection is still not function with Apple's 3.5mm LRGM type phone jack and Apple's headsets:

1. Page0 ,register 13, D6-D5 shows "No headset detected"
2. When we pressing the button of hook and volume up/down on Apple's 3.5mm headset, the detect voltage has no reaction, it keeps 2.5V as we configued to MIC_BIAS all the way.

Would you pls provide your comment to support Apple's 3.5mm headset detection?

Thank you and Best regards,

Wayne Chen
09/14/2016

Hi, Wayne,

Are the connections adapted to the LRGM and Apple's headsets? You must ensure that the jack connections are made correctly. Based on the document Headset Detection for TLV320AIC33 and TLV320AIC3101/4/5/6 Family, the connections must be made correctly. The document shows connections for OMTP headsets. The CTIA connectors must be adapted to this type.

Could you use a OMTP to CTIA adapter to verify if the problem persists? If so, then the connections should be adapted to these jacks.

Best regards,
Luis Fernando Rodríguez S.

Thank you Luis,

We are checking the phone jack connection. Here we have another problem need to consult with you:

1. If we don’t plug in 3.5mm jack headset, the MICBIAS always keep 1.8V, even we try to change Register 25 that setting 2.5V, 3.3V…etc.
2. If we plug in 3.5mm jack headset, the MICBIAS can be controlled by setting Register 25 to 2.0V, 2.5V, and 3.3V.
3. Does AIC3106 support headset detection to compatible with Android 6.0 specification? 

 )





Thank you and Best regards,

Wayne Chen
09/21/2016

Hi, Wayne,

Regarding the points 1 and 2, the MICBIAS pin seems to be working correctly when jack headset is connected. So, when it is not connected, there should be a component that is causing a voltage dropping. I would recommend to verify the MICBIAS path. Please verify if there's a component where the voltage drops when the MICBIAS voltage is increased. I would recommend to start with the diode D25.

Regarding the Android 6.0 compatibility, there are many SHOULDs than are not supported by the device, please take a look at the following list:

- MUST support audio playback to stereo headphones and stereo headsets with a microphone, and SHOULD support audio recording from stereo headsets with a microphone. OK.

- MUST support TRRS audio plugs with the CTIA pin-out order, and SHOULD support audio plugs with the OMTP pin-out order. As mentioned in previous posts, it would be necessary to respect the connections of both jacks. The codec can support both audio plugs, but the connections must be made correctly.

- MUST support the detection of microphone on the plugged in audio accessory, if the device implementation supports a microphone. OK.

- SHOULD support the detection and mapping to the keycodes for the following 3 ranges of equivalent impedance between the microphone and ground conductors on the audio plug. The AIC3106 only supports one key press detection. So, it cannot distinguish a difference between different key press events.

- MUST trigger ACTION_HEADSET_PLUG upon a plug insert, but only after all contacts on plug are touching their relevant segments on the jack. The AIC3106 has a GPIO that enables when a headset is inserted. So, this can be supported too. 

- MUST be capable of driving at least 150mV ± 10% of output voltage on a 32 Ohm speaker impedance. OK.

- MUST have a microphone bias voltage between 1.8V ~ 2.9V. OK.

Please let me know if you have further questions or comments.

Best regards,
Luis Fernando Rodríguez S.

Hello Luis,

Thank you for your elaborate. Regarding to the MIC_BIAS output voltage, we found that if we disconnect the AIC3106's “MICDET” pin,
The MICBIAS can be controlled by Register 25 no matter what 3.5mm jack inserted or not. Would you please advise the hint to identify the MICBIAS voltage be latched at 1.8V.



Thank you and Best regards,

Wayne Chen
09/23/2016