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PCM2912A: PC cannot recognize USB sound card for PCM2912A

user5883945
Expert 1836 points
Part Number: PCM2912A

Tool/software:

Dear,

PCM2912A， During use, after hanging up for about 21 days, the USB sound card suddenly became unrecognizable and connected to a USB device displayed as unrecognizable on the computer. Then, I tested the SSPND pin, which is the 29 pin enable pin, and found it to be 0V.

After replacing the PCM2912A IC, it returned to normal; After solder the abnormal PCM2912A onto the normal board, the board also showed abnormalities. Suspected that the IC was damaged, removed the IC and tested the impedance to GND of each pin of the abnormal IC, as shown in the Excel table. The schematic and PCB are also included in the excel.
Please help investigate the cause of the abnormality and provide suggestions on how to optimize the circuit diagram or PCB design.

PCM2912A debug.xlsx

  • 0
    TI__Mastermind 46535 points

    Hi,

    The schematic is correct and I don't see obvious risks in the layout.

    The low impedance of VDD indicates that some kind of voltage spike damaged the supply pin, causing failure. This will result in failure to be recognized by PC. The power pins are sensitive and can only tolerate 4V before risking damage. 

    Best regards,
    Jeff McPherson

  • 0 in reply to Jeff McPherson
    Expert 1836 points

    Hi Jeff，

      How can we improve reliability？

  • 0 in reply to user5883945
    TI__Mastermind 46535 points

    Hi,

    Clamping diodes can help restrict the power supply to prevent damage. Additional decoupling might be necessary if there is a lot of noise on the supply that causes the voltage to go high. It is best to measure the supply being delivered to the device on start up and during operation to see if there are any high voltage events.

    Best regards,
    Jeff McPherson