Behavior of nRF54L15 During Supply Voltage Transients

[bdub94]

According to the nRF52832 Product Specification, “A step increase in supply voltage of 300 mV or more, with rise time of 300 ms or less, within the valid supply range, may result in a system reset.”

Is there an equivalent consideration or known behavior for the nRF54L15?

I am designing an application powered by a coin cell, and I want to ensure that temporary voltage dips or recoveries (e.g., due to load transients or cell characteristics) do not inadvertently cause a system reset or undefined behavior. Are there any supply slew rate or step change conditions I should account for?

[hmolesworth]

(unofficial) The nRF52832 had a (poor) design choice which used an AC-coupled level to the reset comparator which had the drawback of issuing unexpected resets when a positive VDD voltage jump occurred, as you mention. The nRF54L15 date sheet (v0.8) shows a DC-coupled level to the reset comparator which will therefore not be subject to the same unexpected resets on VDD voltage jumps. It is not known why the nRF52832 would choose such an AC-coupled level to the reset comparator; that choice caused us (and others) multiple design headaches when using a CR2032.

[bdub94]

Many thanks hmolesworth . We'll move forward with our design considering your comment.

Still @Nordic can I get confirmation / an official response?

[Priyanka]

Hi Brian,

The nRF54 series uses a new level triggered reset circuit and does not have this requirement on slew rate/voltage steps in the supply voltage.

-Priyanka