LTE Standard Module Series
EC200U_Series_Hardware_Design 20 / 94
MAIN_RI
62
DO
Main UART ring
indication
V
OL
max = 0.45 V
V
OH
min = 1.35 V
1.8 V power domain.
If unused, keep it
open.
MAIN_DCD
63
DO
Main UART data
carrier detect
V
OL
max = 0.45 V
V
OH
min = 1.35 V
MAIN_CTS
64
DO
DTE clear to send
signal from DCE
V
OL
max = 0.45 V
V
OH
min = 1.35 V
Connect to
DTE’s
CTS.
1.8 V power domain.
If unused, keep it
open.
MAIN_RTS
65
DI
DTE request to send
signal to DCE
V
IL
min = -0.3 V
V
IL
max = 0.6 V
V
IH
min = 1.26 V
V
IH
max = 2.0 V
Connect to DTE’s
RTS.
1.8 V power domain.
If unused, keep it
open.
MAIN_DTR
66
DI
Main UART data
terminal ready
V
IL
min = -0.3 V
V
IL
max = 0.6 V
V
IH
min = 1.26 V
V
IH
max = 2.0 V
1.8 V power domain.
Pull-up by default.
Low level wakes up
the module.
If unused, keep it
open.
MAIN_TXD
67
DO
Main UART transmit
V
OL
max = 0.45 V
V
OH
min = 1.35 V
1.8 V power domain.
If unused, keep it
open.
MAIN_RXD
68
DI
Main UART receive
V
IL
min = -0.3 V
V
IL
max = 0.6 V
V
IH
min = 1.26 V
V
IH
max = 2.0 V
Debug UART Interface
Pin Name
Pin No.
I/O
Description
DC Characteristics Comment
DBG_TXD
12
DO
Debug UART
transmit
V
OL
max = 0.45 V
V
OH
min = 1.35 V
1.8 V power domain.
If unused, keep it
open.
DBG_RXD
11
DI
Debug UART
receive
V
IL
min = -0.3 V
V
IL
max = 0.6 V
V
IH
min = 1.26 V
V
IH
max = 2.0 V
1.8 V power domain.
If unused, keep it
open.
Auxiliary UART Interface
Pin Name
Pin No.
I/O
Description
DC Characteristics Comment
AUX_RXD
137
DI
Auxiliary UART
receive
V
IL
min = -0.3 V
V
IL
max = 0.6 V
V
IH
min = 1.26 V
1.8 V power domain.
If unused, keep it
open.
