Powering DA14580 from regulated 3.3V supply

Hi Dialog,

We intend to power the DA14580 from a 3.7V LiPo battery, and will use an LDO to bring the voltage into the acceptable input range. In the datasheet, the input range for the DA14580 in buck mode is 3.3V. We have used a 3.3V LDO to generate the voltage level for the DA14580. What we notice is that this causes sporadic behavior. Using 3.3V output of a regulator works on several test boards we made, and does not work on several others.

We tested this with a benchtop power supply. If we power the DA14580 from a regulated benchtop supply of 3.2V, everything works correctly. If we power it from 3.3V, then the DA14580 will not boot.

Do you know why this is? Would it be best to use a 3V LDO instead?

Thanks for any input you can provide.