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TLV320AIC3204: tlv320aic3204 headset DAC output with POP noise and white noise

Part Number: TLV320AIC3204

we use headset DAC output to drive the headphone and a class D audio PA .When we use IIS to send PCM data and send the audio out ,the POP noise came at the beginning and the end of the audio. From the PA output we can also hear the white noise. BTW PA gain is 20

  • Hi,

    Welcome to E2E, thanks for your interest in out products!.

    Can you please provide more information of your system like schematic and code used to configure the codec?. Also, Have you disconnected the codec Headphone output to identify if the issue is coming from the codec?.

    A common problem for the DAC outputs when driving an audio amplifier is the out-of-band noise. This phenomenon basically consists on the ADC/Amplifier bringing the out-of-band noise from a DAC back to the audible spectrum. To avoid this a passive filter is recommended at the output of the DAC.  For detailed information about this, please refer to this app note.

    Best Regards,

      -Diego Meléndez López
       Audio Applications Engineer

  • Hi  Diego:

     thank you for your kindness replay.

    we use the recommendate configure to setup our DAC, and  we had tried to disconnect the DAC out signal,and found the AUDIO PA will almost not output the white noise. so we located the issue from codec DAC.

    here is the configure

    # Initialize to Page 0

    w 30 00 00

    # Initialize the device through software reset

    w 30 01 01

    # Power up the NDAC divider with value 1

    w 30 0b 81

    # Power up the MDAC divider with value 2

    w 30 0c 82

    # Program the OSR of DAC to 128

    w 30 0d 00

    w 30 0e 80

    # Set the word length of Audio Interface to 20bits PTM_P4

    w 30 1b 10

    # Set the DAC Mode to PRB_P8

    w 30 3c 08

    # Select Page 1

    w 30 00 01

    # Disable Internal Crude AVdd in presence of external AVdd supply or before

    #powering up internal AVdd LDO

    w 30 01 08

    # Enable Master Analog Power Control

    w 30 02 00

    # Set the REF charging time to 40ms

    w 30 7b 01

    # HP soft stepping settings for optimal pop performance at power up

    # Rpop used is 6k with N = 6 and soft step = 20usec. This should work with 47uF coupling

    # capacitor. Can try N=5,6 or 7 time constants as well. Trade-off delay vs “pop” sound.

    w 30 14 25

    # Set the Input Common Mode to 0.9V and Output Common Mode for Headphone to

    # Input Common Mode

    w 30 0a 00

    # Route Left DAC to HPL

    w 30 0c 08

    # Route Right DAC to HPR

    w 30 0d 08

    # Set the DAC PTM mode to PTM_P3/4

    w 30 03 00

    w 30 04 00

    # Set the HPL gain to 0dB

    w 30 10 E2

    # Set the HPR gain to 0dB

    w 30 11 E2

    # Power up HPL and HPR drivers

    w 30 09 30

    # Wait for 2.5 sec for soft stepping to take effect

    # Else read Page 1, Register 63d, D(7:6). When = “11” soft-stepping is complete

    # Select Page 0

    w 30 00 00

    # Power up the Left and Right DAC Channels with route the Left Audio digital data to

    # Left Channel DAC and Right Audio digital data to Right Channel DAC

    w 30 3f d6

    # Unmute the DAC digital volume control

    w 30 40 00

    and the SCH

  • Hi,

    Thanks for the feedback and additional information. From what I can see, the codec configuration is fine and schematic seems good, however, the out-of-band noise filter i pointed out before is not included.  Can you please try adding the filter at the codec outputs after the decoupling cap and see if the noise in the amplifier is decreased?, a 100Ω Resistor and 47nF cap combination should work fine.

    Best Regards,

      -Diego Meléndez López
       Audio Applications Engineer