User's Manual

LTE Module Series
EC21 Hardware Design
EC21_Hardware_Design Confidential / Released 26 / 94
COEX_UART_
TX
138 DO
LTE/WLAN
coexistence signal
V
OL
max=0.45V
V
OH
min=1.35V
1.8V power domain.
If unused, keep it
open.
WLAN_SLP_
CLK
118 DO WLAN sleep clock
If unused, keep it
open.
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.
If unused, keep it
open.
BT_EN* 139 DO
BTfunctioncontrolvia
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
pad
50ohm impedance
If unused, keep it
open.
ANT_MAIN 49 IO Main antenna pad 50ohm impedance
ANT_GNSS 47 AI GNSS antenna pad 50 ohm 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
the module.
If unused, keep it
open.
W_DISABLE# 4 DI Airplane mode V
IL
min=-0.3V 1.8V power domain.