ADSP SC587 VDD_RTC current consumption

Can anyone tell me how much current would the ADSP SC587 RTC section will consume from VDD_RTC rail? This is just to estimate the coin cell life time.

  • The RTC module will consume around ~10 uW power on VDD_RTC power rail. But please note that this is not a fully characterized power number but you can use it in your calculation for estimating the cell life.

    Regards,

    Nabeel

  • Hi Nabeel,

    So the RTC module will consume around 3.3 uA current from the 3.3V rail right ? The reference manual says that the RTC section itself having one internal voltage switch over circuit so that it will automatically switch over to IO supply whenever processor IO supply is above certain threshold . So could could you please confirm in which scenario the maximum current consumption from coin cell will happen ? and does the 10uW accounts to the scenario where no processor IO supply is present ? !

  • 10 uW is the power consumption of RTC module on 3.3V rail. It doesn't matter which domain is it working from. Is is correct that the RTC module switches from the VDD_RTC to VDD_EXT when VDD_EXT is above certain voltage. So in that case when it switches to VDD_EXT, there will be almost no current drawn form VDD_RTC (which is from Coin Cell).  Maximum current will be drawn from Coin cell only when VDD_EXT is off.

    Regards,

    Nabeel