Product Info

LPWA Module Series
BG95 Series Hardware Design
BG95_Series_Hardware_Design 51 / 106
VCCA VCCB
OE
A1
A2
A3
A4
A5
A6
A7
A8
GND
B1
B2
B3
B4
B5
B6
B7
B8
VDD_EXT
MAIN_RI
MAIN_DCD
MAIN_RTS
MAIN_RXD
MAIN_DTR
MAIN_CTS
MAIN_TXD
51K
51K
0.1uF
0.1 μF
RI_MCU
DCD_MCU
RTS_MCU
RXD_MCU
DTR_MCU
CTS_MCU
TXD_MCU
VDD_MCU
Translator
10K
120K
Figure 17: Main UART Reference Design (Translator Chip)
Please visit http://www.ti.com/ for more information.
Another example with transistor translation circuit is shown as below. For the design of circuits in dotted
lines, see that of circuits in solid lines, but please pay attention to the direction of connection.
MCU/ARM
TXD
RXD
VDD_EXT
10K
VCC_MCU
4.7K
10K
VDD_EXT
MAIN_TXD
MAIN_RXD
MAIN_RTS
MAIN_CTS
MAIN_DTR
MAIN_RI
RTS
CTS
GND
GPIO MAIN_DCD
Module
GPIO
EINT
VDD_EXT
4.7K
GND
1nF
1nF
Figure 18: Main UART Reference Design (Transistor Circuit)
Transistor circuit solution is not suitable for applications with high baud rates exceeding 460 kbps.
NOTE