PCM1860: PCM1860 AD，PCM5142 DA, Simulated output amplitude decreases

已经收到了您的案例，调查需要些时间，感谢您的耐心等待。

I wrote it wrong, DA. I'm not using PCM5142, but PCM5242

Hi jingchao，

I have consulted with a specialized engineer for you. This is a response to PCM5142. Due to system issues, I did not receive any follow-up notification from you. If you are using PCM5242, please be patient and wait for a new response from the specialized engineer.

Hello,

Here are few suggestions to debug the issue:

1_Confirm that if you put a full scale analog input at input of ADC, you get all ONEs at the output of the ADC for each channel  ( this is to make sure there is no attenuation set from ADC  ) Single-Ended, 2.1-VRMS 

2_ Similarly you can send a digital FS (All ONEs ) to the DAC, and see if you get FS or still FS/2? Similarly make sure there is no attenuation is set in DAC ( for example the DAC can has -6dB attenuation according to Table 3. Gain and Attenuation in Hardwired Mode). Also note that PCM514x provides 2.1-VRMS ground centered outputs

Basically, you  need to confirm if there is an issue,   is it related to  the DAC side or ADC.

It is important to confirm the above first. 

Once you confirmed there is no issue with the above items  , then we can move on to the following;

1-Please share more information about the I2S signals. For example what is Fs and BCLK and channel depth. 

2-Confirm that the data format is indeed I2S  for BOTH  ADC and DAC ( both in register  set up and actual data send in to DAC ( if you format is not what it is supposed to be, MSB can be missed or move to LSB of the previous channel (LJ to I2S or I2S to LJ and things like this) Please screen  capture the I2S signal edges as depicted in Figure 16 of  DAC datasheet .

Regards,

Hi，

PCM5142 or PCM5242 does not change the situation much.

So customer  confirmed  ADC has no attenuation. Still they need to go through my post and follow the rest of above requests and report back the result  so we can do the  debug with full data.

Specially I am interested in the format of digital out from ADC and the set format for DAC.

Regards,