Quectel EG91 Series Hardware Design page 48

V
OL
V
OH
The module provides 1.8V UART interfaces. A level translator should be used if customers' application is
equipped with a 3.3V UART interface. A level translator TXS0108EPWR provided by Texas Instruments is
recommended. The following figure shows a reference design.
Please visit http://www.ti.com for more information.
Another example with transistor translation circuit is shown as below. The circuit design of dotted line
section can refer to the circuit design of solid line section, in terms of both module input and output circuit
design. Please pay attention to the direction of connection.
EG91_Series_Hardware_Design
0
1.35
Figure 20: Reference Circuit with Translator Chip
LTE Standard Module Series
EG91 Series Hardware Design
0.45
1.8
V
V
47 / 106