TAS6422E-Q1: Connect SDIN to GND, the output still has waveform and noise.

Alan,

Please tell us what these waveforms are.  Ther is no label.  I am assuming these are each output relative to ground.  If so, the speaker would not see these as it is common-mode.  Is the frequency of the waveform 1.412Hz or 1412 Hz.  I is difficult to read this.

Hi Gregg,

To correct a little information, the above problem occurs on TAS6422E.
In addition, I will update the question information: Your understanding is correct, the above waveform is indeed the output to the ground. But I still don't quite understand why the input port of the audio data is connected to GND, and why the output of the 6422 has a PWM waveform at this time? There is an analog signal at both ends of the speaker?

Hi Derek，

Due to network issues with my computer, I am currently unable to upload test images and videos.

I went to the DEBUG site and as we discussed in the afternoon, the current phenomenon and inspection are as follows:

The current issue is that there is a noticeable noise phenomenon when the Headunit is turned on, in the audible frequency band.
(1) Measure the OUT of 6422E and find the PWM waveform of D change. Subsequently, connect SDIN to GND, and the PWM terminal still has the same waveform as mentioned above.
(2) After removing the filtering network that was inconsistent between the customer's output and the reference design, the phenomenon did not disappear.

I currently have two suspicious points:
(1) There is an error in the timing of the customer's CLOCK, which can be verified by playing I2S on the computer;
(2) The actual format used is not I2S, and the SAP register configuration is incorrect;
(3)  I cannot connect to the customer's 6422E I2C using the PPC TAS6424&6421 app. Do I need to apply for a 6422E app to connect to the customer's 6422E I2C to configure the customer's board.

If that's the case, could you please help me download the 6422E app to PPC to help customers test it.