• TI Thinks Resolved

TAS2557: No audio output from TAS2557 in custom board

Prodigy 90 points

Replies: 10

Views: 80

Part Number: TAS2557

Hi Team,

Issue : No audio output from TAS2557 in custom board.

Description:
The driver is installed in Linux environment and there is no calibration file at the moment. The SoC acts as I2S master and there is a external DSP and TAS2557 interfaced as I2S slave.
The SoC and external DSP are working well.

Setup:
1. MCLK - 8.2MHz
2. Sampling rate - 8KHz
3. I2S data width - 16 bit

Kernel log:
i2c client is ok.
pTAS2557 created
Yes valid
PG2.1 Silicon found
i2c 1-004c: FW Size = 16746
i2c 1-004c: Checksum = 0xC605881A
i2c 1-004c: PPC Version = 0x5C000
i2c 1-004c: FW Version = 0x1010000
i2c 1-004c: Driver Version= 0x0300
i2c 1-004c: Timestamp = 1601623451
i2c 1-004c: DDC Name = firmware_8khz
i2c 1-004c: Description = TI SmartAmp
i2c 1-004c: find default configuration 0
i2c 1-004c: tas2557_set_bit_rate: nBitRate = 16
i2c 1-004c: load program 0 (Tuning Mode)
i2c 1-004c: TAS2557 load data: Tuning Mode Program, Blocks = 1, Block Type = 1
i2c 1-004c: TAS2557 load block: Type = 1, commands = 2867
i2c 1-004c: Block[0x1] PChkSum match
i2c 1-004c: Block[0x1] YChkSum match
i2c 1-004c: load PLL: pll block for Configuration configuration_Tuning Mode_8 KH z_s1
i2c 1-004c: TAS2557 load block: Type = 0, commands = 15
i2c 1-004c: load configuration configuration_Tuning Mode_8 KHz_s1 conefficient p re block
i2c 1-004c: TAS2557 load data: Snapshot 1, Blocks = 2, Block Type = 4
i2c 1-004c: TAS2557 load block: Type = 4, commands = 7
i2c 1-004c: Block[0x4] YChkSum match
i2c 1-004c: load new configuration: configuration_Tuning Mode_8 KHz_s1, coeff bl ock data
i2c 1-004c: TAS2557 load data: Snapshot 1, Blocks = 2, Block Type = 3
i2c 1-004c: TAS2557 load block: Type = 3, commands = 536
i2c 1-004c: Block[0x3] YChkSum match
i2c 1-004c: tas2557_update_edge, edge: 4
i2c 1-004c: tas2557_setup_clocks: nSamplingRate = 8000 [Hz]
i2c 1-004c: Sampling rate for current configuration matches: 8000
i2c 1-004c: tas2557_calibration_get = 0
i2c 1-004c: Enable: 1
i2c 1-004c: Calibration 0 doesn't exist
i2c 1-004c: Enable: load startup sequence
i2c 1-004c: Enable: load unmute sequence

Hardware Test:
1. VBAT = VBOOST VREG = 3.65V
2. Tested the MCLK, BCLK, WCLK,SDIN in Oscilloscope the signals seem valid

  • Hi, jvasanthan,

    Our team will take a look at this and will provide an answer as soon as possible.

    Best regards,
    Luis Fernando Rodríguez S.

  • In reply to Luis Fernando Rodriguez S.:

    Hi,

    I managed to get the sound output from the speakers but the audio output sound level seems low. I tested by playing a pink noise file (see attached) and measuring with a calibrated sound level meter.When I play the pink noise in TAS2557EVM I get about 90 dBA whereas with my custom board I get about 82 dBA. I checked the gain settings in address 0x6 it is set to 0xf.

    is there any other settings I should check?  How to resolve this?

  • In reply to jvasanthan:

    Hi jvasanthan,

    Are you using the same speaker for both tests? Is the connection to the speaker very different from the EVM to your application (are you using any filter)?

    Perhaps you can try by setting the device into ROM mode to check if the attenuation is due to algorithm.

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

  • In reply to Ivan Salazar:

    Hi Ivan,

    Yes, I am using same speaker for both the tests. I don't have LC filter at the output, I have 0 ohm resistors (in place of ferrite bead and no capacitors ) placed in series to the speaker terminals. is that ok?

    Yes I will try ROM mode. should I try ROM1 or ROM2?

    Regards,

    James

  • In reply to jvasanthan:

    HI James,

    Any of the ROM modes would be OK for this test.

    In addition, can you share the PPC3 file you use to generate your configuration files? If you have many snapshots please also let us know which one you're using.

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

  • In reply to Ivan Salazar:

    Hi Ivan,

    I have attached the ppc3 file. I used the default tas2557evm PPC3 file. 

    TAS2557_pg2p1_48000_aacv2_vC4.ppc3.txt

  • In reply to jvasanthan:

    Hi James,

    I'll inspect the file, but it would be good to know the results after you test with ROM mode in both the EVM and your custom system, this can help us verify if the difference in amplitude is due to the speaker protection algorithm.

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

  • In reply to Ivan Salazar:

    Hi Ivan,

    I tested ROM mode 1 in both EVM and custom board. When I play the pink noise in TAS2557EVM I get about 80 dBA whereas with my custom board I get about 72 dBA. What can we infer from that?

  • In reply to jvasanthan:

    Hi James,

    This means you're getting a stable 8dBA difference regardless of device configuration, so difference is not coming from speaker protection algorithm.

    Can you share your schematic and layout if possible? Also could you share some photo of the test setup for the EVM and your custom board?
    From amplifier standpoint there should be no difference, if possible please also share a register dump of book 0 page 0 from both setups just to make sure there is no difference between them.

    You can reach out directly over private message or email if don't want to post your files on the forum: ivan.salazar@ti.com

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

  • In reply to Ivan Salazar:

    Hi James,

    Let me follow up offline on the email thread we started. I'll close this thread for now but will get back here with the final results for the community information.

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