PCM1795: 2Pcs PCM1795 Connection

Wenting Wu

Intellectual 2090 points

Part Number: PCM1795
Other Parts Discussed in Thread: PCM1794A

Hello Sir,

One of my customer gona to use 2pcs PCM1795 to achieve 4CH output. Could you help to check their connection?

TDMCA mode can transfer both control signal and audio signal. Does it mean under TMDCA mode, PCM1795 register can be visited?

Shown as below block diagram, LRCK, BCK, SCK are used by both PCM1795s. If the second PCM1795's DI connected together and used to transfer control signal and audio data. DO feedback MCU's data and is connected together as well. the 1st PCM1795's DCO is connected to the second PCM1795's DCI.

If you have more material to talk about 2 pcs PCM1795 used in parallel. Please send for me the material.

Many thanks for your help!

over 3 years ago

0 Paul_Frost over 3 years ago

TI__Guru 53313 points

Hi Wenting,

I do not actually have much experience with the TDMCA mode for these device, as most customers implement SPI or I2C to control multiple devices. What I find in the datasheet, this is the correct way to connect the devices. The TDMCA mode can access any device register. Figure 75 goes into some detail about this.

Thanks,

Paul

0 Wenting Wu over 3 years ago in reply to Paul_Frost

TI__Intellectual 2090 points

Hello Paul,

Is PCM1795 the best DAC in TI? Can i help my customer to apply 2 EVM of PCM1795?

Best regards,

wenting

0 Wenting Wu over 3 years ago in reply to Wenting Wu

TI__Intellectual 2090 points

Hello Paul,

Thanks for your quick reply!

Could you also help to recommend someone who have experience on daisy chain of PCM1795 or other similar audio DAC? I've helped my customer to check their connection again and modify as the attachment according to your comments, but I' still not sure. I saw there is a post to talk about PCM1795 daisy chain https://e2e.ti.com/support/audio/f/6/t/241708 and an ID named Patrick Galvin to support with.

Best regards,

wenting

0 Paul_Frost over 3 years ago in reply to Wenting Wu

TI__Guru 53313 points

Hi Wenting,

We do not have any PCM1795EVMs in stock right now, but we are ordering more, which we will have in about 2-3 weeks.

The PCM1795 is one of the highest performing devices in the DAC portfolio, though the PCM1794A/2A are slightly higher performing.

I will try to review some of the TDMCA information over the weekend. This mode is not used very often, so we do not have much experience in supporting it.

Thanks,

Paul

0 Wenting Wu over 3 years ago in reply to Paul_Frost

TI__Intellectual 2090 points

Hello Paul,

Thanks for your review.

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PCM1795: 2Pcs PCM1795 Connection