DA7212 turns off Line out when both channels are connected

HI,

I have very strange issue with custom-made audio board based on DA7212.

Using Raspberry Pi to drive card, Aux input for recording works fine, Line out gives nice and clear sound on both channels.

I am connecting Line out from board to home stereo system and if I connect only one channel, works for hours.

When I connect second channel to my stereo, audio plays for approx. 5 seconds and then both channels are switched off. As soon as I disconnect one channel, audio continues.

Schematic of Line out on my board is very simple, 

Does anyone have idea what is happening here? 

Could be some Lineout protection mechanism in DA7212 that is cutting off load due to some protection?

Is there any test I can do or components to add to check if this is on PCB side or externally?

I am stuck here so any suggestion will be appreciated

  • Found solution for this behavior and it has nothing to do with DA7212 chip (or PCB). My amplifier has some strange input filter when input level is below 100mV for 2-3 seconds it disconnects input. When it sense higher level, it turns input on. Thing was that I was testing at low level in Volumio software + ALSA setting was at 0dB level, resulting in output level in range of 50-150mV. Once I raised levels to 300+mV, everything works fine. This is very strange filter but that is probably what you get when buying "cost effective" amplifiers.

  • The DA7212 audio codec disables the Line Out when both channels (left and right) are connected simultaneously. This issue might stem from a design feature or a potential fault in the codec’s circuitry, causing it to prioritize one output or misinterpret the dual connection as an error. A workaround or hardware modification may be required to maintain consistent Line Out functionality.