PCM1808 Startup Problem

Wayne Chen (Audio AE)

Other Parts Discussed in Thread: PCM1808

Hi Sirs,

We got the PCM1808 startup problem in slave, I2S mode which needs your suggestion.

Please refer to the schematic and screen capture:

Power Up Sequence (CH1=5V VCC, CH2=3.3V VDD, CH3=MCLK, CH4=BCLK), PCM1808 MD0=MD1=FMT=GND
SOC sends MCLK, BCLK, LRCK only when music playback, the PCM1808' does not send valid Vref (only 1V), the PCM1808 does not send DOUT (always low)

Power Up Sequence: 5V, 3.3V startup earlier than MCLK and BCLK

Music Startup

Music Playback:

Thank you and Best regards,

Wayne Chen
11/02/2016

over 8 years ago

0 Diego Melendez over 8 years ago

TI__Guru 57800 points

Hi, Wayne,

Sorry for the delay, I have notified the engineer in charge to take a look to this issue, he will contact you soon.

Best Regards,

-Diego Meléndez López
Audio Applications Engineer

0 Shuo Cao over 8 years ago

Prodigy 120 points

Hello Wayne,

have you figured out the problem with Vref? I actually also get very low Vref at startup with MCLK and BCLK keeping low. And for now I do not have a MCU or DSP which is sending signals to the PCM1808. Will the Vref increase its voltage level to 0.5Vcc when the PCM1808 starts to operate?

Thanks a lot!
Shuo

0 Wayne Chen (Audio AE) over 8 years ago in reply to Shuo Cao

TI__Genius 15950 points

Thank you for your concern, Shuo. We have solved this problem by removing improper Voltage divider at PCM1808's input on customer's system board...Wayne Chen

Audio

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PCM1808 Startup Problem