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PCM5102: PCM5102 Left/Right independent control in HW mode

Jaydon Chae
Prodigy 60 points
Part Number: PCM5102
Other Parts Discussed in Thread: PCM5101, PCM1798

Tool/software:

Hi All,

I'm using PCM5102 with H/W conorl mode and I2S format.. as below 

But at this condition, I can't contorl Left and Right independenlty by Input source. 

For example, when I put 1V to Left and Right input, there is all 1V to Left and Right output bu when I mute Left input and keep 1V to only Right channel input, there is all 500mV to Left and Right output together.

Thhis situaition is the same for Right channel(Left 1V and Right input mute--> Left and Right otuput are all 500mV)..

CouId I get any supporting on whether there is something wrong that I'm missing or PCM5102 is doing such a situation in H/W mode(If yes, PCM5101 can overcome this one by pin to pin with PCM5102?

Help to get your suipporing and your feedback will be highly appreciated.

Thanks in advance.

Best regards,

Jaydon 

  • 0
    TI__Mastermind 33650 points

    Hi Jaydon,

    Our expert on this part is out of office today and will return Monday to answer your question.

    Thanks for your patience,
    Jeff McPherson

  • 0 in reply to Jeff McPherson
    TI__Mastermind 24300 points

    Hi Jaydon,

    If you have data when LRCLK is high but no data when LRCLK is low, then you should not see any data on the channel with no data  (unless there is a mixer which I don't think this device has it. 

    If you send a 1V @1KHz sinewave, do you see a +0.5Vp sinewave on L and R or one output  is inverted and differentially it makes 1V? Probably looking at LRCLK, Din  and outputs on the  scope can shed light on this. 

    Some of our parts have dedicated pin to switch b/w mono and stereo. One part that can be  used is PCM179x, for example PCM1798 has this  dedicated pin,  and I think this is what you are looking for. Also  TAD5242 , from our new family of our devices,  can do this via pin MD6. Most device that are SW controlled  can achieve independent volume control as well as mute too.

    I noticed SCK is floating in your schematic, if you are  planning to use the  PLL mode ,  the SCK  should be grounded.

    Regards,

    Arash

  • 0 in reply to Arash Loloee
    Prodigy 60 points

    Hi Arash,

    Thanks for your advice..Following by your advice, I tested LRCK and Data by each input mute of Left and Right after pull-down of SCK.. 

      

    1. Left and Right inputs are all enable.

    2. Left input mute and only kepping Right input

    3. Right input mute and only keeping Left input

    As you see above, the data input has been changed by each channel input muting but the output is still all 0.5V output into Left/Right channel. It's like mono mixing in IC internally... And even in all Left/Rigth chananel inputs and when there is  1Vrms to Left and 2Vrms to Right independently, the output is all 1.5Vrms into Left/Right.. 

    As I said, I'm using PCM5102 in hardward mode. In my opinion, PCM5102 can't support stereo in hardware mdoe. And to surely identify it, could you help to confirm that  PCM5102 is not possible to control strereo output in hardware mode?'

    Help to get your feedback

    Thanks 

    Best regards,

    Jaydon

  • 0 in reply to Jaydon Chae
    TI__Mastermind 24300 points

    hi Jaydon,

    Thanks for providing the extra data point. Seems it sends a mono signal to both channels . As far as I know, this is supposed to be a true stereo part and I have not had any reference to this kind of behavior in the past.

    Let me see if I can find an EVM and test it from my end . I will  give you a confirmation by next week this time.

    Regards,

    Arash

  • 0 in reply to Arash Loloee
    TI__Mastermind 24300 points

    Hi , I had the EVM for this part in the lab and was able to do a quick check with a 1KHz, 1Vrms signal and as I expected it is a true stereo device. I can send the inputs to both channels or mute one channel at a time and accordingly the full  output shows on the expected channel or channels. I am not sure what is going on with your board or set up but as I said I have never heard of mono performance for this device the way you see it and my tests confirmed that.  

    Stereo vs Mono.zip

    I would suggest to get the dedicated EVM and start from there and move on to your own board.

    Regards,

    Arash