I know this has been discussed, in the xmega forum, but has anyone experience on this?
My board should output wav files on the speakers of something resambling an ATM.
I'm using a 3W class-D amplifier for the speakers. Wav files are from a sd card.
Everything works now just fine, but I'm using a codec in-between the micro and the amplifier.
This way I can output very high quality audio, but this is not truly neccessary.
I'm thinking of using the xmega DACs for direct output, but I'm afraid of the resulting "quality".
This would save board cost and complexity.
Also, someone said of using the 1V reference for the DAC. But from what I understand the theory, this would get 1Vpp which is only 0.35Vrms.
The amplifier inputs which are "line in" standard are 1Vrms which is 2.82Vpp, so the DAC should be used with VDDA (3.3V) reference.
Of course, the coupling should be AC with capacitors.
Am I missing something?
Anyway the big question is: is 12bit high enough for such application? Think that you will go to some bank ATM and it will give you some voice messages and a pleasant melody on its 3W speakers