Telit Wireless Solutions GE863-QUAD Manual Do Utilizador

 
 
 
 

 

 

 1vv0300715 Rev. 1 - 19/09/06  

  

Reproduction forbidden without Telit Communications S.p.A. written authorization - All Right reserved 

 

page 28 of 79 

 

 
The RS232 serial port lines are usually connected to a DB9 connector with the following layout: 

 

6.4  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, but since the 
translation requires very few components, then also a discrete design can be suited. For example a 
possible inexpensive translator circuit for a 5V driver can be: