TAC5242: TAC5242 Codec AGND / DGND

Jaslau

Part Number: TAC5242

Hello,

for our new design I have seperate AGND and DGND connections. Can anybody tell me, if VSS of the TAC5242 is better be connected to AGND or DGND? Also the VREF capacitor, DREG capacitor and the capacitors when in AC-coupled Line single-ended connection (I guess AGND) and MD0-4.

I am using TPS7A2033 for AVDD and OPA1678D for input and output buffering. OPA1678D is referenced to AGND (bypass caps), TPA7A2033 has a digital VDD input but is also connected to AGND. The microcontroller is connected via I2S.

I appreciate your help. Thanks!

28 days ago

0 Jeff McPherson 28 days ago

TI__Mastermind 48805 points

Hi Jaslau,

All the grounds get tied together internally, so it doesn't really matter between AGND and DGND as long as you don't put them all on a single ground.

For example I would split it like this:

A1, A4 -> AGND

A2, A3 - DGND

VREF should be referenced to AGND since it is part of the analog front end circuit

DREG is the digital regulator output. Reference to DGND

Not sure what you mean by referencing an AC coupling cap to ground. If you're talking about surrounding the trace with the correct GND, use AGND for the analog inputs

MDx pins are digital pins so they should be referenced to DGND

Best regards,
Jeff McPherson

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TAC5242: TAC5242 Codec AGND / DGND