Quectel BC68 User Manual

GSM/GPRS/NB-IoT Module Series
BC68&M66 Compatible Design
BC68&M66_Compatible_Design 20 / 31
4.7. UART Interfaces
The voltage domain of UART interface for BC68 is different from that of M66. The following is the voltage
domain of the modules.
Table 5: UART Interface Voltage Domain
The following is a reference design of the UART interface when the application processor communicates
with M66 via UART interface. It is recommended to add a level match circuit between the module and the
DTE, because of the different power domain of their UART interface. For details, please refer to
document [4].
DCD-B
RI-B
CTS-B
TXD-B
DCD
RI
CTS
TXD
DCD-A
RI-A
CTS-A
TXD-A
VCC-A
M66
Module
VDD_EXT
VCC-B
VCC
DCD
RI
CTS
RXD
VCC
DTETranslator
GND GND-A
GND-B GND
DBG_TXD-A
DBG_TXD
DBG_RXD
DBG_TXD-B
RTS-B
DTR-B
RTS
DTR
RTS-A
DTR-A
RTS
DTR
DBG_RXD-A
DBG_RXD
DBG_TXD
DBG_RXD-B
RXD-B
RXD
RXD-A
TXD
Figure 12: Reference Design of M66 UART Interface
Module
UART Interface
Voltage Domain
Description
M66
Main UART&
Debug UART
2.8V
Support RTS/CTS
BC68
3.0V
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Quectel BC68 Specifications

General

Brand	Quectel
Model	BC68
Category	Control Unit
Language	English