MC57xxPSIA with TAS5708EVM

siavash rezaei1

Other Parts Discussed in Thread: PCM1808, TAS5708

Hi,

I have purchased the TAS5708EVM which comes with MC57xxPSIA to evaluate TAS5708 + PCM1808 combination.

The analog input on MC57xxPSIA which is through PCM1808 generates high levels of background noise. The digital inputs are fine, which leads me to think it is problem of PCM1808 chip.

I have tried different high quality regulated power supplies, but that didn't help.

Are these levels of noise natural with PCM1808 chip?

Does these evaluation board represent the best performance possible for TAS5708 + PCM1808 combination?

over 11 years ago

0 Don Dapkus over 11 years ago

TI__Guru**** 189399 points

Hi, Siavash,

What level of noise do you measure at the outputs?

You are changing the jumper at JP4 when you change the input source, right?

-d2

0 siavash rezaei1 over 11 years ago in reply to Don Dapkus

Prodigy 185 points

Hi Don,

What level of noise do you measure at the outputs?

I haven't hooked it up to a scope yet. I'll do that tomorrow and post the results.

You are changing the jumper at JP4 when you change the input source, right?

Yes. I do get sound but with a pretty loud background "hiss"

Siavash

0 siavash rezaei1 over 11 years ago in reply to siavash rezaei1

Prodigy 185 points

Hi Don,

It was an issue with my setup :)

0 Ravi Singh over 11 years ago in reply to siavash rezaei1

TI__Mastermind 22965 points

Hi Siavash,

Can you please provide details on what the setup issue was?

Thanks,

Ravi

0 siavash rezaei1 over 11 years ago in reply to Ravi Singh

Prodigy 185 points

Hi Ravi,

I didn't look into the problem in detail, but it was caused by the USB connection from the computer to the board.

When I disconnect the USB the noise goes away.

0 Don Dapkus over 11 years ago in reply to siavash rezaei1

TI__Guru**** 189399 points

Aaaaaaah, the dreaded ground loop; the bane of audio engineers everywhere!

-d2

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MC57xxPSIA with TAS5708EVM