PCM1789-Q1: Audio Section DAC review

deepak upadhyay

Part Number: PCM1789-Q1
Other Parts Discussed in Thread: PCM1789

Hi ,

For our design We have used PCM1789-Q1 in our design. I have completed the schematic and reviewed it my side.

It will be better for our design if TI can also review the schematic for the same . I am attaching the Schematic snip, Please share any Inputs from TI.

Thanks,

over 6 years ago

0 Paul_Frost over 6 years ago

TI__Guru 53623 points

Hi Deepak,
The schematic looks good.
We also recommend a LPF on the outputs of the PCM1789 with an fC of ~.5fS. Ideally this would be a 2nd order active filter, but a RC may be acceptable in the application as well.

Thanks!
Paul

0 deepak upadhyay over 6 years ago in reply to Paul_Frost

Prodigy 65 points

Thanks Paul,

I have Given RC circuit at the input of Power amplifier TAS5411QPWP , A combination of 1uf and 50K ohm at both the outputs ,"AMP_IN_P" & "AMP_IN_N".

so that should be okay i suppose.

In Layout ,Do i need to place RC near to output of PCM1789 or Input of power amplifier TAS5411QPWP ?Please confirm.

0 Paul_Frost over 6 years ago in reply to deepak upadhyay

TI__Guru 53623 points

Hi Deepak,

The TAS5411 recommends the 1µF for DC blocking (HPF) and the 49.9kΩ to keep the inputs from floating during POR events. I recommend that you implement a low-pass filter in addition to these, on the PCM side of the DC blocking capacitor.

The placement of these components in the layout will not really impact performance as long as they are fairly isolated from high frequency switching signals.

Thanks!

Paul

0 deepak upadhyay over 6 years ago in reply to Paul_Frost

Prodigy 65 points

Hi Paul,

Thanks, For your Valuable comments .

Can I go with the same combination , 680E and 10nf That you mentioned in upper image ?

Thanks

0 Paul_Frost over 6 years ago in reply to deepak upadhyay

TI__Guru 53623 points

Yes. That filter is targeting fC =~20kHz, which is ideal for 44.1k or 48k sample rates.

Thanks!

Paul

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PCM1789-Q1: Audio Section DAC review