User's Manual

Telit GE863-QUAD / GE863-PY
Hardware User guide
1vv0300715, Rev. ISSUE#0, - 21/02/06
Reproduction forbidden without Telit Communication written authorization – All Right reserved – Right of modification reserved page 25 of 71
5.4 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:
and for a 5V receiver: