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PCM1794A-Q1: PCM1794A-Q1 bipolar zero error spec

Ryuuichi machida
Guru 11515 points
Part Number: PCM1794A-Q1

Hi,

I would like you to confirm about meaning of following spec which is described in datasheet of PCM1794A-Q1.

* bipolar zero error.

I will show example circuit and could you please confirm following my understanding is correct ?

--

* Feedback resistance is implemented 470 ohm.

* So BPZ(BiPolar Zero) is approximate -2.91V.

Then, I believe following bipolar zero spec is defined as shown below.

--

If you have uncleared point about my example, please let me know.

Best Regards,

Machida

  • 0
    TI__Guru 57800 points

    Hi, Machida-san,

    The bipolar zero error refers to the percentage of FS that the zero point of the output signal will drift, so your assumption seems correct. 

    Best Regards,

      -Diego Meléndez López
       Audio Applications Engineer

  • 0 in reply to Diego Melendez
    Guru 11515 points

    Hi Diego-san,

    Thank you for your reply.

    I have additional question about center output current.

    * My customer faced problem which is voltage of BPZ is shifted 6 - 8 % from expected voltage.

    According to previous thread, I understood that voltage of BPZ may be shifted due to bipolar zero error. However, regulation of above is not within  bipolar zero error spec.

    So, is there any factor which regulation of above will happen except bipolar zero error spec ?

    Best Regards,

    Machida

  • 0 in reply to Ryuuichi machida
    TI__Guru 57800 points

    Hi, Machida-san,

    Correct, the expected shift should be within the specified limits on the bipolar zero error spec. Can you please check with your customer for the input signal integrity to discard any problems related to the input of the device?. 

    Best Regards,

      -Diego Meléndez López
       Audio Applications Engineer

  • 0 in reply to Diego Melendez
    Guru 11515 points

    Hi Diego-san,

    Thank you for your reply.

    >Can you please check with your customer for the input signal integrity to discard any problems related to the input of the device?.

    I could ask above question to customer, but I'm not sure what you want to confirm. Do you concern about timing requirement of input signal ?

    If so, I can just confirm customer's input signal, because there is no description about min and max...

    BR,

    Machida

  • 0 in reply to Ryuuichi machida
    Guru 11515 points
    Hi Diego-san,

    I'm sorry I forgot to describe important item.

    * "My customer faced problem which is voltage of BPZ is shifted 6 - 8 % from expected voltage."
    Above condition is observed when customer do not input any signal (This means silent condition.)

    So, we can not confirm any input signal.
    Is there any possibility that this condition will happen ?

    BR,
    Machida
  • 0 in reply to Ryuuichi machida
    Guru 11515 points
    Hi Diego-san,

    According to datasheet, I believe that only bipolar zero error indicates output error for center output.
    So, I think that there is no factor which center output will shift due to PCM1794A-Q1 itself except "Bipolar zero error".

    However, if you have any other parameters which will cause error for center output on datasheet spec, could you please let it me ?

    BR,
    Machida