Quectel LC79D

GNSS Module Series
LC79D Hardware Design
LC79D_Hardware_Design 16 / 42
Standby Mode Control
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
NSTANDBY
5
DI
Standby mode
control
V
IL
min=-0.3V
V
IL
max=0.35×VCC
V
IH
min=0.65×VCC
V
IH
max=VCC+0.3V
Active low.
Pulled up by default.
UART/SPI Interface
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
TXD/
SPI_CLK
2
DO/DI
Transmit data/
SPI clock
V
OL
max=0.4V
V
OH
min=VCC-0.45V
V
OH
nom=1.8V
V
IL
min=-0.3V
V
IL
max=0.35×VCC
V
IH
min=0.65×VCC
V
IH
max=VCC+0.3V
LC79D (A): UART
LC79D (B): SPI
RXD/
SPI_CS
3
DI/DO
Receive data/
SPI chip select
RTS/
SPI_MISO
22
DO
Request to send/
SPI master in
salve out
CTS/
SPI_MOSI
23
DI
Clear to send/
SPI master out
slave in
RF Interface
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
RF_IN
11
AI
RF signal input
50Ω characteristic
impedance.
I2C Interface*
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
I2C_SDA
16
OD
I2C serial data
V
IL
max=0.35×VCC
V
IH
min=0.65×VCC
V
OL
max=0.4V
V
OH
min= VCC-0.45V
V
OH
nom=1.8V
Require external pull-
up to 1.8V.
If unused, keep
these pins open.
I2C_SCL
17
OD
I2C serial clock
INT
18
DI
External interrupt
input
V
IL
min=-0.3V
V
IL
max=0.35×VCC
V
IH
min=0.65×VCC
V
IH
max=VCC+0.3V
If unused, keep this
pin open.
Other Interfaces
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment