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LM49450: Asking for the LM49450 no output issues

SHH
Mastermind 30301 points
Part Number: LM49450
Other Parts Discussed in Thread: PCM5100

Hi Team,
Cusotmer uses LM49450 and cusotmer found there is no output at the headphone.

On the I2S bus, there is also PCM5100 DAC. PCM5100 can output signal normal. So, cusotmer think I2S is good.

Would you please review the schematic and provide your comment how to resolve this issue?
txn.box.com/.../2amq2nru4wamdvridi5zkpzsa6vf0nt3
txn.box.com/.../3af8ti3zjuslpr5nf1vom71plyia86x5

MCLK : 12.288Mhz

WS : 48khz

BCK : 3.072Mhz

BR,
SHH

  • 0
    TI__Guru* 95445 points
    Hi SHH,

    The schematics seem to be correct. Could you share the device register configuration?
    Have you tried to read back register values to verify that I2C is working correctly for LM49450?

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators
  • 0
    Prodigy 10 points
    For that I have some different tricks, so for that if you interested with it then you will do one thing you just reset the whole settings and after that you will be very helpful. For further just visit : epsonsupports.net/.../
  • 0 in reply to Ivan Salazar
    TI__Mastermind 30301 points
    Hi Ivan,
    Do you have the LM49450 initial script for example?

    BR.
    SHH
  • 0 in reply to SHH
    TI__Mastermind 30301 points
    Hi Ivan,
    customer only set register0x00 =0x21.
    Do you have any initial script for example?

    BR,
    SHH
  • 0 in reply to SHH
    TI__Guru* 95445 points
    SHH,

    It is recommended to write into all related register to their desired use case.
    There are some register default values that might not be what customer need, like registers 0x07 and 0x08 that set LS and HP gain to the lowest level.
    Unfortunately there is no sample init script for this device.

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators
  • 0 in reply to Ivan Salazar
    TI__Mastermind 30301 points
    Hi Ivan,
    Would you please review the initial setting as below? Please provide you comment for the setting if missing.
    00 21
    01 00
    02 49
    03 00
    04 00
    05 00
    06 00
    07 14
    08 14
    09 00
    0A 00
    0B 00
    0C 00
    0D 00
    0E 00


    Do you have LM49450 EVM that can provide us for verification?

    BR,
    SHH
  • 0 in reply to SHH
    TI__Guru* 95445 points
    SHH,

    The settings you've shared are pretty much the default settings, only changing the gain and device enable.
    Unfortunately I don't have any EVM to share with you or to test it myself.
    I also noticed that data sheet, does not explain Bit 1 from Register 0x00 (LINE_IN). I'll try to get this information although it might be difficult to find (this happens with most of LM devices).

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators