Part Number:TAS5825M
Questions
My question is, other than a short circuit (which is not the case here), what can cause a TAS5825M to lock-up with an over current fault that cannot be cleared even after cycling the power?
My follow-up question is what can be done to clear an over current fault that otherwise refuses to go away?
Details
We are using a TAS5825M on a board we developed. For now our processor is a Raspberry Pi. Our board provides the I2S clocks. The sample clock rate is 48KHz. The Pi is configured so that it does not generate the clocks. It took us a while but we have a stable ALSA configuration that enables us to use commands such as 'aplay' to playback WAV files and 'mpg123' to playback MPG files. We can play back 44.1KHz and 48KHz files.
We have a speaker connected to the TAS5825M left channel. We have a 10K resistor instead of a speaker on the right channel. We have configured the TAS5825M to mix L+R for both channels.
Recently we installed an open-source program that enables streaming to the Pi via Apple's airplay protocol. The program is called shairport-sync. Our clocks produce a 48KHz sample rate, but shairport-sync can only playback at 44.1KHz. To accommodate this we configured an ALSA plugin to do the necessary conversion. It took us a while to sort things out, but we finally got shairport-sync to playback without any errors being reported. However, there was no sound. When we then used 'play' we still did not get any sound. Something "broke".
We inspected the TAS5825M registers and found register that register 0X70 was reporting 0x02, which means left channel over current fault. We tried clearing the fault using register 0x78 but that did not work. We were able to clear the fault using register 0x01, but as soon as we executed 'aplay' the fault reappeared. Of course we did things like cycle the power, but that did not work either. Eventually we unsoldered the chip and replaced with a new chip. The new chip worked as long as we did not use shairport-sync and the ALSA conversion plugin.
Any help you can provide would be most appreciated.
Respectfully,
Robert Seliger
WHIM LLC