STA311b PSCorrect question

[bernhard23]

Posted on November 01, 2014 at 21:15

Hello, I'm using a STA311b DSP in my actual Project and I'm wondering how the powersupply correction works? I couldn't find any details about this feature. How do I have to connect the ADC in this case? Do you have a sample shematic for this?

Thanks in advance,

best regards

Bernhard

[Nickname1623_O]

Posted on November 06, 2014 at 08:29

hi Bernhard,

regarding the power supply ripple correction feature , you need to use an ADC (left channel of stereo audio ADC) to sampling ripple level on the power supply rail for power stage , then fed data into STA311B SDI78 input , the  data 7 will be used for ripple info .

and you need to set PSC parameter for CNV and RCV accordingly. please pay attention for max ripple peak measurement , it should be measured when output is unclipping ( close to 1% THD) .

Thanks

[bernhard23]

Posted on November 08, 2014 at 20:05

Hello Zhao,

thank you for your fast reply. I will try this in the lab. You don't have a example for the configuration?

Another question: The sta311b has a I2S recombination interface. What does it do? I never heard about such a Feature and the datasheet does not say very much about it. Can I use it to compare two I2S signals like a analog audio signal with a differential op amp to correct errors?

Thanks

[Nickname1623_O]

Posted on November 10, 2014 at 04:47

hi Bernhard ,

yes we have example for this function , please find it attachment.

the I2S recombination is a mixer with level detection , this feature was focusing on the high dynamic microphone application , due to microhpone was not easy to senselow level sound and without clipping with high level sound input , then different sensitivity input signal mixing can expend microphone recordingdynamic range withbetter SNR.

it's not suitable for feedback application

Thanks

________________

Attachments :

Presentation1.pdf : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006Ht1o&d=%2Fa%2F0X0000000aJ2%2FANKpPQIj1maDPyVEJ7I0pIxsuEfImy6cKAZouBCL.Ns&asPdf=false

[bernhard23]

Posted on November 11, 2014 at 15:51

Hi Zhao,

thanks a lot for the attachment. That's how I did it. I Input a ripple into my power stage supply and see the ripple at the Output of the amp on my spectrum analyzer. Next I take the power stage supply and feed it into a low noise, well filtered op amp with a high gain. If I put the Output of this opamp into my spectrum analyzer I get a really nice spectrum of my injected ripple. So that's fine. Now I Input this to the adc and feed my SDIN7 but I don't get the values for Register 51 to 53 calculated. Do you have a example for it, too? You would help me a lot... Everything I tried ended in a high THD or in nothing.

Thanks a lot.

Regards

Bernhard

[Nickname1623_O]

Posted on November 18, 2014 at 10:21

Hi Bernhard ,

regarding the register calculation , please find detail in attachment .

Thanks ,

________________

Attachments :

psc_calcualtion.pdf : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006Ht1t&d=%2Fa%2F0X0000000aJ3%2FC_yqD0w8_KbL25Vcs2Di2ttTOF.aUUjnKpSwI90nQvM&asPdf=false

[bernhard23]

Posted on November 19, 2014 at 16:14

Hello,

thanks a lot you really helped me. I got it now :) Great feature!!

[lds330]

Hello Mr. BernHard,

I have same question as Mr. Zhao. But where is the attachments? I cannot find it in your chat history. Can you please attach the example and register calculation again? or you can just send a email to me: [e-mail], thank you so much.

David.