User Manual

GE863-PRO
3
Hardware User Guide
1vv0300773a Rev. 1 DRAFT - 24/04/08
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 22 of 82
NOTE: don't use any pull up resistor on the RESET*-GSM line nor any totem pole digital output. Using pull
up resistor may bring to latch up problems on the GE863-PRO3 power regulator and improper functioning
of the module. The line RESET*-GSM must be connected only in open collector configuration.
TIP: The unconditional hardware reboot should be always implemented on the boards and software
should use it as an emergency exit procedure.
For example:
1- Let's assume you need to drive the RESET*-GSM ( RESET ) pad with a totem pole output of a +3/5
V microcontroller (uP_OUT2):
4.4 Turning ON/OFF the GE863-PRO
3
ARM
To turn on the GE863-PRO
3
ARM the pad ON_OFF*-ARM must be tied low and kept low, when pin is
raised ( released ) the ARM will shutdown.
The maximum current that can be drained from the ON_OFF*-ARM pad is 0,1 mA.
A simple circuit to do it is:
10k