adau1962a  reduce the mute period

I am using the SC589 startkit, which there is a adau962a DAC. After the DAC was enabled, it took about 30ms that signal appread at the out pin. I think the mute period is too long for our application, is there a way to reduce the mute period, thank you

  • Hello ADI_XUN,

    First of all, how long is too long? What number are you looking to meet?

    I am not very familiar with this board. I am the support person for the DAC but not the DSP. I just looked at the schematic. I see what looks like a PLL clock source, U25, That is supplying the master clock for the DAC. I also see that it is supplying 24,576MHz.

    The DAC is NOT in standalone mode so I do not know what mode it is being set to since it depends on the system controller to set the registers and turn on the part. So this is probably part of the delay, the DSP has to wake up and then program the DAC.

    The DAC has an internal PLL that may be turned on. It is recommended to have it on. This PLL can take up to 10ms to lock. The outputs will be muted until lock is achieved.

    The PLL that is supplying the master clock will also have a startup time.

    So I think you need to look closely at when the master clocks come up and when the DSP communicates with the DAC and see how long that all takes.

    If you ran the DAC in the direct clocking mode you may be able to shave off some time. But, it does take some time for all the DAC bias voltage to come up to nominal value. 30ms is pretty fast so that is why I am wondering how fast does your application require?

    Thanks,

    Dave T