User's Guide

HE863 Family Hardware User Guide
1vv0300891 Rev.5
- 2011-03-18
Reproduction forbidden without Telit Communications S.p.A’s. written authorization - All Rights
Reserved. Page 32 of 89
desirable stability, HE863 Family needs at least 10 seconds
after the PWRMON goes High.
Following time charts can be referred according to the
application design.
i. First time supplying the power more than 3.2V to Vbatt
By only first time supplying the power to Vbatt line, the
HE863 Family will power on without toggling ON/OFF# pin.
ii. Using ON/OFF key when USB interface is not used
If the application will not use the usb interface of HE863
Family, that is, actually the usb interface is not connected
between the devices, the hold time to tie ON/OFF# to GND
should be 1 ~ 2 sec to make it powering on.