Quectel EG21-G - Page 26

LTE Module Series
EG21-G Hardware Design
EG21-G_Hardware_Design 25 / 100
VDD_SDIO
34
PO
SD card SDIO bus
pull-up power
I
O
max=50mA
1.8V/2.85V
configurable.
Cannot be used for
SD card power.
If unused, keep it
open.
BT UART Interface*
BT_RTS*
37
DI
BT UART request to
send
V
IL
min=-0.3V
V
IL
max=0.6V
V
IH
min=1.2V
V
IH
max=2.0V
1.8V power domain.
If unused, keep it
open.
BT_TXD*
38
DO
BT UART transmit
data
V
OL
max=0.45V
V
OH
min=1.35V
1.8V power domain.
If unused, keep it
open.
BT_RXD*
39
DI
BT UART receive
data
V
IL
min=-0.3V
V
IL
max=0.6V
V
IH
min=1.2V
V
IH
max=2.0V
1.8V power domain.
If unused, keep it
open.
BT_CTS*
40
DO
BT UART clear to
send
V
OL
max=0.45V
V
OH
min=1.35V
1.8V power domain.
Cannot be pulled up
before startup.
If unused, keep it
open.
BT_EN*
139
DO
BT function control
via FC20 module
V
OL
max=0.45V
V
OH
min=1.35V
1.8V power domain.
If unused, keep it
open.
RF Interface
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
ANT_DIV
35
AI
Diversity antenna
50Ω impedance
If unused, keep it
open.
ANT_MAIN
49
IO
Main antenna
50Ω impedance
ANT_GNSS
47
AI
GNSS antenna
50Ω impedance
If unused, keep it
open.
GPIO Pins
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
WAKEUP_IN
1
DI
Sleep mode control
V
IL
min=-0.3V
V
IL
max=0.6V
V
IH
min=1.2V
V
IH
max=2.0V
1.8V power domain.
Cannot be pulled up
before startup.
Low level wakes up