RTOS/PCM2903C: Can't work normally from S3 wake up at PCM2903C.

Hi, Hugo,

Could you please elaborate more on the issue of the device?. Is the PCM2903C not detected by the host system?. Have you tried to use your board with a different OS?.

I reviewed the schematic, in general seems fine but I noticed an incorrect connection for SEL1 pin, as it should be connected to Vbus of the USB bus.

Best Regards,

  -Diego Meléndez López
   Audio Applications Engineer

Hi Diego sir

Please refer as followings. Thanks.

Could you please elaborate more on the issue of the device?

        Line in of PCM2903C can’t work from S3 wake up, must enter S5 or enter S4 and then resume system, It can work normally.

Is the PCM2903C not detected by the host system?

        System can find the device from device manage from S3 resume. You can see the following picture.

Have you tried to use your board with a different OS?

        Base on customer request, Win7 64 bit is failed. Please give me your comment if this solution has OS limit. I don’t find information from datasheet.

I reviewed the schematic, in general seems fine but I noticed an incorrect connection for SEL1 pin, as it should be connected to Vbus of the USB bus.

        Vbus is +V3.3, So your meaning is delete R7797 and connect SEL1 to VBUS directly? Right? 

Hi, Hugo,

Thanks for the feedback. Can you please explain about the S3 wake up process? how is this done?.

Regarding the SEL1 pin, I meant to connect it to the Vbus signal of the USB bus, not the device pin. The SEL1 pin requires to detect the USB bus connection to start the attach process, as indicated in figure 36 of the datasheet.

Best Regards,

  -Diego Meléndez López
   Audio Applications Engineer