Quectel RG520N-AT - Page 57

5G Module Series
RG520N-AT_Hardware_Design 56 / 109
The following figure illustrates the reference design for Bluetooth UART.
Module
Bluetooth
BT_TXD
BT_RXD
BT_RTS
BT_CTS
BT_UART_RXD
BT_UART_TXD
BT_UART_RTS
BT_UART_CTS
Figure 27: UART Connection
The module provides 1.8 V UART. A voltage-level translator should be used if the application is equipped
with a 3.3 V UART.
MAIN_RXD
70
DI
Main UART receive
MAIN_RI
100
DO
Main UART ring indication
MAIN_DTR
258
DI
Main UART data terminal
ready
MAIN_DCD*
261
DO
Main UART data carrier
detect
BT_TXD*
59
DO
Bluetooth UART transmit
BT_RXD*
63
DI
Bluetooth UART receive
BT_RTS*
61
DI
Request to send signal to
the module
Connect to the
peripheral’s RTS.
1.8 V power domain.
BT_CTS*
62
DO
Clear to send signal from
the module
Connect to the
peripheral’s CTS.
1.8 V power domain.
DBG_RXD
108
DI
Debug UART receive
1.8 V power domain.
DBG_TXD
105
DO
Debug UART transmit