LTE-A Module Series
EG12 Hardware Design
EG12_Hardware_Design 49 / 97
Table 14: Pin Definition of the BT UART Interface
3.11.4. UART Application
EG12 provides 1.8V UART interfaces. A level translator should be used if the 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.
The logic levels are described in the following table.
Table 15: Logic Levels of Digital I/O
Pin Name
Pin No.
I/O
Description
Comment
BT_EN
3
DO
BT function enable control
1.8V power domain
If unused, keep it open.
BT_TXD
163
DO
Transmit data
BT_CTS
164
DO
Clear to send
BT_RXD
165
DI
Receive data
BT_RTS
166
DI
Request to send
Parameter
Min.
Max.
Unit
V
IL
-0.3
0.6
V
V
IH
1.2
2.0
V
V
OL
0
0.45
V
V
OH
1.35
1.8
V
