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PCM1802 - minus PCM data

Hirotaka Matsumoto
Guru 27585 points
Other Parts Discussed in Thread: PCM1802

Hi all,

Would you mind if we ask PCM1802?

Our customer use PCM1802 with following settings;

<Each pins setting>
BYPASS=HIGH/Bypass (dc component on DOUT )mode
FMT1-0:00 Left-justified, 24-bit
MODE1-0:00 Slave mode
LRCK: fs=96kHz
BCK: 64fs
SCKI: 256fs
FSYNC: High
OSR: Low
VCC: +5V
Vdd: +3.3V

Voltage sequnece is the following.
1. VDD
2. Vcc

Our customer would like to use external DC input(bias) to VinR or VinL.  
Then, after that, the voltage 2.4V is added to VinR or VinL.
PCM data is "1111 1011 0200 0xxx xxxx x000" minus data.

Audio ADC is for AC coupling, so but if you have some advice, could you let us know it?

We have to hurry to it.
We appreciate your help.

Kind regards,

Hirotaka Matsumoto

  • 0
    TI__Mastermind 27990 points
    Hi Hirotaka,

    When inputting AC signals to an audio ADC you want to remove any DC bias with a AC coupling cap. This allows the AC content alone to get captured, which after the AC coupling cap will get biased by the input circuit. Why do they need the input to be biased to something other than what the PCM1802 will expect?

    Justin