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TAS2770EVM: PWM output for 1KHz input

Part Number: TAS2770EVM
Other Parts Discussed in Thread: TAS2770

Hello Concern,

I want to check the the PWM output for 1KHz input source file.

What will be output, Because i am getting fixed frequency out along with 5V amplitude as VBAT is 5V.

SBCLK to FSYNC - 256

SAmple rate - 44.1KHz

SBCLK - 12.96MHz 

  • Hello  Shubham Jagtap2,

    Welcome to E2E and thank you for your interest in TAS2770. I will take a look at this issue.

    It seems like the device is not output any audio content. If it is output properly, you should able to the the output PWM with changing duty cycles. 

    May I ask how you are controlling the EVM? USB or external?

    On a side note, the SBCLK seems slight off from the proper configuration. According the Table 75 of the datasheet, SBCLK should be 11.2896 MHz for future reference.


    Jin Gao

  • Hello Jin,

    Thanks for the response.

    We are getting the audio output. but while measuring the PWM output Frequency is constant ( Not changing the duty cycle).

    We are controlling the EVM through USB.

    Can please share the basic configuration setting i. SBCLK, FSYN & Sampling rate.

    Kind Regards,

    Shubham Jagtap

  • Hello,

    May I ask if the audio output is working? (able to play a test tone or sound/music through the speaker?)

    In addition, do you have the scope capture of the output available?

    -TAS2770 requires initialization from PPC3. Make sure it the button "power up" is selected in PPC3>Device Control

    -The playback is set according to the user guide

    Regarding SBCLK, FSYNC & sampling rate, as long as your Auto_Rate is enabled the device should be fine. Take a look at this table from the datasheet. If improper SBCLK or ratio is detected, it will ramp down the volume.



  • Hello Shubham Japtap2,

    Thank you for contacting us on E2E. I'm closing this E2E thread due to the inactivity. However, please feel free to post your questions or comments in case of additional observations.


    Jin Gao