TS3A227E: TS3A227E use hardware mode control for pass through mode
Part Number: TS3A227E
I have a headset which is not properly working with the TS3A227E. Tip-to-Sleeve resistance is 1.46 kOhm and Tip-to-Ring2 is 18 Ohm. According to this post it should be a standard (CTIA) headset:
However, its only detected as 3-pole. I also managed to setup some resistors on a 4-pole plug for simulating a headset and I have similar problems. Although this setup will be most of the times be recognized as a standard (CTIA) headset, sometimes the TS3A227E states it is only a 3-pole.
What could be the problem?
Best regards, Thorben
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In reply to Adam Torma:
Dear Adam,thank you for your answer.
Adam TormaDo you have the model of the headset that is being detected incorrectly?
Adam TormaWhich resistor values are being detected incorrectly?
Adam TormaCan you quantify how many times you mean sometimes?
Adam TormaHow are you monitoring the TS3A227E to know if 3-pole or 4-pole is recognized by the part?
In reply to Thorben Vornholz:
Adam TormaHow are you initiating the detection sequence in your testing?
Adam TormaThe third thought is that the connection of the headset to the jack is not great.
Adam TormaDo you have a picture of your board or set up?
In the attached schematic I see you are properly using the SJ-435107RS isolating switch on pins 5 and 6 of X1502. When a headset is inserted into X1502, the pull down resistor on pin 6 will connect and pull down the TS3A227E det_trigger pin to initiate the detection sequence. Using the 2 second debounce setting should account for any issues with slow plugging an audio jack.
With the 4-pole headset permanently plugged into the audio jack and you manual trigger the detection sequence does this always detect as a 4-pole headset?
How many times does this incorrectly detect as a 3-pole?
When it incorrectly detects as a 3-pole, without doing another manual detection, does reading 0x0B again fix the issue or does register 0x0B always return 3-pole once it incorrectly detects? I'm trying to see if maybe you are reading the register before the detection is complete and the 0x0B register is updated.
Dear Adam,good to hear that the hardware looks fine. I tried a lot of different things to track it down a bit further. It somehow seams to be a problem with the 4-pole plug of the headset. Plugging the headset in an short selfmade extension cable and connecting this to my device doesn't cause any problems. Besides that I also tried your approach of manually triggering the detection sequence. See the attached scripts for details.man_trigger.sh is basically sequence 2 on page 22 of the manual and I used it as well as it is intended by having nothing plugged in at first and pluggin in the headset after event 2. I also used it while leaving the headset attached and ran the script several times. I've done the same for the re_trigger.sh script and it looks like that, once one type is detected, it does not change by triggering the detection again. Only unplugging and plugging it back again changes the type.
Adam TormaHow many times does this incorrectly detect as a 3-pole?
it looked like the headset is causing trouble. Today, I had my setup disassembled in between, I saw 3-4 false detections even with the extension cable. It's strange, because it doesn't add that much of extra impedance to the setup. So I wouldn't blame the headset for the issue since I've now seen the issue with the extension cable as well and also some customers complaining about that issue with their smartphone headsets.
In previous test I noticed some significant crosstalk during simultaneous playback and recording with this headset. By adding the extension cable, the crosstalk increases by ~13 dB because the wires are not bundled. Is it possible that this somehow improves the detection mechanism?
Please try to reproduce the error on your side.
have you been able to reproduce the error?
if you're unable to reproduce it, could you please tell me, how I can change the detection state of TS3A227E via software/register settings? Refering to SCDA014 it should be possible to change the state from 3-pole to 4-pole or from OMTP to CTIA but I don't know how. Please tell me the exact register settings I have to set because all of my previous attempts failed.
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