PCM1794: Using 20-bit DSP in PCM1794 digital filter bypass mode

Pavao Lubina

Part Number: PCM1794
Other Parts Discussed in Thread: PCM1792A

Hello,

We've been using DSP with 20-bit output to feed our PCM1794 (configured to work in internal digital filter bypass mode).

Output signal is about 24dB lower than expected, so we guess that PCM1794 doesn't handle this situation as we expected and shifts the MSB to 4 bit lesser place.

Is there some way to configure PCM1794 to support 20-bit source in digital filter bypass mode?

Thanks

Pavao

over 7 years ago

0 Paul_Frost over 7 years ago

TI__Guru 53633 points

Hi Pavao,

You could potentially accomplish this with some external digital logic components to shift the WDCK four BCK periods to accomplish this. You could also consider the digitally controlled PCM1792A device, which support the 20-bit mode.

Thanks!
Paul

0 Pavao Lubina over 7 years ago in reply to Paul_Frost

Prodigy 60 points

Thanks for suggestions. I'll see what I can do.

Best,

Pavao

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PCM1794: Using 20-bit DSP in PCM1794 digital filter bypass mode