RE: nRF52833 slow boot at 1.8V

alison.lloyd — Fri, 12 Mar 2021 11:21:25 GMT

Thanks Kenneth, that's interesting. We're doing some further investigation into VDD ramps, and I'll update here once I have further data.

RE: nRF52833 slow boot at 1.8V

Kenneth — Mon, 08 Mar 2021 15:20:20 GMT

Hi,

I can't find that we have any electrical parameters for the startup times as function of supply voltage directly. We only specify the typical value and max value as function of the VDD rise time:

I am not surprised if starting 1.8V takes a longer than starting at 3.3V, since there are decoupling capacitors that need to charge and reach a defined level before POR is released, and these capacitors will reach rise faster if the voltage difference is larger. The table above also show that the startup time can vary a lot, and the supply voltage level is one factor of this.

Based on the above table it can take up to 110ms before POR is released if the rise time is max 60ms. Also notice that the POR can release before supply have settled (23ms < 60ms).

Best regards,
Kenneth