User's Manual

Table Of Contents
GC864 Hardware User Guide
1vv0300874 Rev.0 – 2010-01-25
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved. Page 39 of 64
The RS232 serial port lines are usually connected to a DB9 connector with the
following layout:
9.3. 5V UART Level Translation
If the OEM application uses a microcontroller with a serial port (UART) that works at
a voltage different from 2.8 3V, then a circuitry has to be provided to adapt the
different levels of the two set of signals. As for the RS232 translation there are a
multitude of single chip translators. For example a possible translator circuit for a 5V
TRANSMITTER/RECEIVER can be: