GE/GC864-QUAD V2 and GE864-GPS Hardware User Guide
1vv0300915 Rev.5 – 2011-10-03
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved.
Page 58 of 94
NOTE:
The digital input lines working at 2.8V CMOS have an absolute maximum input voltage of
3.0V; therefore the level translator IC shall not be powered by the +3.8V supply of the
module. Instead, it must be powered from a +2.7V / +2.9V (dedicated) power supply.
This is because in this way the level translator IC outputs on the module side (i.e. GE/GC 864
inputs) will work at +3.8V interface levels, damaging the module inputs.
NOTE:
In order to be able to do in circuit reprogramming of the GE/GC 864 firmware, the serial port
on the Telit GE/GC 864 shall be available for translation into RS232 and either it's controlling
device shall be placed into tristate, disconnected or as a gateway for the serial data when
module reprogramming occurs.
Only RXD, TXD, GND and the On/off module turn on pad are required to the reprogramming
of the module, the other lines are unused.
All applicator shall include in their design such a way of reprogramming the GE/GC 864.
An example of level translation circuitry of this kind is:
