Hi, we are using this device in a hw design that has been proven with another processor. The prototype board we now have has problems with the audio out on HS and HD channels.
When using a mic and enabling digital loopback, I can hear audio, but only by cranking all gains to max, including the 23dB preamp. Even then, the audio is poor quality, with constant buzzing in the background (the buzzing varies with the digital volume settings, so is not from my external hw).
When looping back the same data in the processor (i.e. DIN = DOUT), I don't hear any audio at all. Sidetone works fine and audio is clear and loud.
We have checked all of the mute/volume settings, we are using A-law for both the ADC and DAC, we have checked the timeslot settings, etc. We are using I2C for control data; there is only one device, but is set up as a master due to its tight timing requirements
Can someone provide any more advice or guidance?
Thanks,
Brian
