PCM2912A: PCM2912A Malfunction in System <20% Low Battery Mode But Normal 5V Vbus Voltage

Wayne Chen (ex FAE)

Part Number: PCM2912A

Hi Sirs,

My customer encounters a PCM2912A malfunction problem in system <20% low battery mode while the 5V Vbus still in regulation.

Vbus is 4.8V in this condition. The system can recognize PCM2912A UAC device on USB_CDC_D-/+. However, there is no analog output from PCM2912A.

Customer follows up PCM2912A's reference schematic. Audio architecture plays music stream by UAC interface.
With UAC path, speaker Playback Volume shows -1 in abnormal condition:

Abnormal speaker volume

Normal speaker volume

Would you please provide tips to identify this problem and the process to identify the PCM2912A in normal operating conditions?
We can send schematic by Email as needed.

Thank you and Best regards,

Wayne Chen
01/09/2019

over 5 years ago

0 Ravi Patil over 5 years ago

TI__Expert 5645 points

Hi Wayne,
PCM2912A should operate at nominal 5V but it should operate at 4.8V which is much higher than the min spec. We will look into what else may be causing the issue w UAC abstraction to cause this issue.

Please do send the SCH via email...and any additional details that you may think to be relevant while we look into the issue more. Thanks.

Best regards,
Ravi

0 Wayne Chen (ex FAE) over 5 years ago in reply to Ravi Patil

Guru 15950 points

Thank you Ravi. I just sent customer's schematic by Email...Wayne Chen

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PCM2912A: PCM2912A Malfunction in System <20% Low Battery Mode But Normal 5V Vbus Voltage