Hardware Guide

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FIBOCOM MC610 Series Hardware Guide 41/71
3.6.2 UART Interface Application
The serial port level of MC610 series modules is 1.8 V by default. If the level of the customer host
system is 3.3 V or others, it is necessary to add a level converter in the serial port connection between
the module and the host. The following figure shows the design of reference circuit using level
conversion chip:
Figure 3-14 UART signal connection 1
Another level conversion circuit is shown in the following figure. The design of input and output circuits of
the following dotted line part can be with reference to the solid line part, but pay attention to the
connection direction.
Figure 3-15 UART signal connection 2