A customer is having power sequencing problems with the AIC3254:
We are powering the LDO input and the IO Vdd from separate supplies, and the LDO input could be active at +3.3V long before the IOVDD of 1.8V is active. We are however, using the IO VDD to turn on the LDO enable pin. TI has recently released SLAA492A “TLV320AIC32x4 Power Supply Sequencing” in which they call for IO Vdd to be present before AVDD and DVDD. The LDO_Select line is not mentioned in this app note, so I cannot be sure whether or not I can use it to ensure correct power sequencing. With our setup, the HPVdd to the headset drivers will be on before IOVdd. Again, HPVdd is not really mentioned other than for headphone pop (we are not using the headphone amp)
Please advice.
