ADAU1962 Popping noise after Power-ON

Hi,

I'm moving your thread to the correct community.

Cheers,

Ivan

Dear Team,

Could you please share the your feedback on this issue.

Hello RameshMarisa,

On this post I see you are using the EZ Kit so that answers my question I left on the other post where you asked the same question.

I will discuss this with the designer. It does take some time for the DAC outputs to come up to the common mode voltage but this eval board does use the suggested DAC output filter from the datasheet.

So I will investigate and get back to you. It will probably be later next week before I have an answer.

Dave T

Dear DaveThib,

Could you please share the your feedback on this issue.

RameshMarisa,

I wanted to confirm if your configuration code follows the sequence shown in the POWER UP AND RESET section of the ADAU1962 datasheet?  Looking at the configuration code, it seems the MMUTE bit is set to 0 (in DAC_CTRL0) before the PUP bit is asserted to 1 (in PLL_CTL_CTRL0).  

Dear galvinpjg,

Thank you for your information and support.

Our configuration code is as per POWER UP AND RESET section of the ADAU192 datasheet. In our configuration code, ADAU_1962_Pllinit() routine called first. In this routine only PLL control registers are configured (PUP bit as 1). The default value of the MMUTE bit is 1 after Power-ON. We are clearing MMUTE bit to zero (0) after completing all registers configurations.

Hello RameshMarisa,

I have been working on this in the lab and have not come up with a solution as of right now. I have not given up yet. What I am noticing is that from a cold start, all power off, I get a pop when the power up bit is enabled. Once it is powered up and I send the same sequence it is quiet. If I disable the power up bit and then re-enable it but did not remove the power to the part I get very little pop. Slight pop that would probably be acceptable.

Is this the same behavior you are seeing?

Dave T

Dear DaveThib,

We get pop up only when power up bit is enabled from a cold start. This pop up seems like either capacitor charging or discharging. We didn't observe the pop up when disable and enable the power up bit without removing the power to the part.

Thanks