User's Guide

LE910Cx HW User Guide
Doc#: 1VV0301298
Rev. 13.0 Page 51 of 124 2019-07-15
NOTE:
Consider voltage drop under max current conditions when defining the
voltage detector threshold in order to avoid unwanted shutdown.
The most important thing is that a system should give sufficient energy LE910Cx turns off
safely during 30ms after the Fast Shut Down is triggered. If not, unwanted memory
corruption can be happened. VAUX pin can be used to check if LE910Cx is turned off. If
VUAX is low, LE910Cx is turned off.
The following formula can be used to calculate Ctank value to give LE910Cx sufficient
energy during the Fast Shut Down.
LE910Cx consumes up to 800mA and 30ms is the typical time to execute the shutdown
and 1V is the minimum voltage margin from threshold of LE910Cx hardware reset. Based
on the formula, more than 24mF is needed for the Fast Shut Down.
But the Ctank value should be optimized depending on the detection voltage and load
current LE910Cx consumes in customer’s system.