Service Guide

LTE Standard Module Series
SD_SDIO_DATA2
29
DIO
SD card SDIO bit 2
SD_SDIO_DATA3
28
DIO
SD card SDIO bit 3
SD_SDIO_VDD
34
PO
SD card SDIO power
supply
SD_DET*
23
DI
SD card hot-plug detect
1.8 V power
domain. If
unused, keep it
open.
Main UART Interface
Pin Name
Pin No.
I/O
Description
DC
Characteristics
Comment
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 (Connect to
DTE’s CTS)
V
OL
max = 0.45 V
V
OH
min = 1.35 V
MAIN_RTS
65
DI
DTE request to send
signal to DCE (Connect
to DTE’s RTS)
V
IL
min = -0.3 V
V
IL
max = 0.6 V
V
IH
min = 1.2 V
V
IH
max = 2.0 V
MAIN_DTR
66
DI
Main UART data terminal
ready
MAIN_RXD
68
DI
Main UART receive
MAIN_TXD
67
DO
Main UART transmit
V
OL
max = 0.45 V
V
OH
min = 1.35 V
Debug UART Interface
Pin Name
Pin No.
I/O
Description
DC
Characteristics
Comment
DBG_RXD
11
DI
Debug UART transmit
V
IL
min = -0.3 V
V
IL
max = 0.6 V
V
IH
min = 1.2 V
V
IH
max = 2.0 V
1.8 V power
domain.
If unused, keep
it open.
DBG_TXD
12
DO
Debug UART receive
V
OL
max = 0.45 V
V
OH
min = 1.35 V
I2C Interface
Pin Name
Pin No.
I/O
Description
DC
Characteristics
Comment
I2C_SCL
41
OD
I2C serial clock
Used for