PMC1794A + PCM1798

Cheok Loon Lee

Other Parts Discussed in Thread: PCM1798, PCM1794A, TAS5624A, TAS5508C, PCM1794, TAS5624, TPA1517

Hi,

Can I use PCM1794A (FL/FR) with 2 more PCM1798 for a full 5.1ch? Not sure if this will cause any delay effect between both chips. So i'm guessing it should be the same since it comes from the same family. Are there any documentations on this implementation and delay specs?

Main idea of using this is to get better SNR compared to multichannel DACs

Lee

over 13 years ago

0 Don Dapkus over 13 years ago

TI__Guru**** 189399 points

Hi, Lee,

Why don't you use a completely digital solution like TAS5508C driving three pieces of TAS5624A? No D/A conversion until you get at the speaker!

-d2

0 Cheok Loon Lee over 13 years ago in reply to Don Dapkus

Intellectual 610 points

Hi Don,

Thank you for the recommendations. But this project is going to be a soundcard and I only needed Line out. Also it would be built on previous soundcard project which is using PCM1794A for stereo. Now we are considering adding 1798 for multichannel.

Any idea if this has any issue?

Lee

0 Patrick Galvin over 13 years ago in reply to Cheok Loon Lee

TI__Genius 16270 points

Lee,

The main source of delay would be the group delay of the digital filters, shown on page 4 of both datasheets. They are different for the two devices, with PCM1794 at 55/fs or 18/fs for sharp or slow rolloff respectively, and PCM1798 at 38/fs for both.

0 Seng Chai Soh over 13 years ago in reply to Don Dapkus

TI__Prodigy 700 points

Don,

Very interesting suggestions to use TAS5508C+TAS5624 for a 5.1 Soundcard???

0 Cheok Loon Lee over 13 years ago in reply to Patrick Galvin

Intellectual 610 points

Patrick,

Any idea if this combination can pass dolby Digital requirements?

0 Patrick Galvin over 13 years ago in reply to Cheok Loon Lee

TI__Genius 16270 points

Lee,

These parts have been used before successfully in Dolby Digital applications. Please note however that decoding will need to be done separately by the processor.

0 Don Dapkus over 13 years ago in reply to Patrick Galvin

TI__Guru**** 189399 points

SC,

Need I remind you of the TPA1517's history?!?!?! :)

-d2

0 Seng Chai Soh over 13 years ago in reply to Don Dapkus

TI__Prodigy 700 points

Don, can't really remenber that...its Steven Chai's time...

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PMC1794A + PCM1798