User's Manual

SIM7090G User Manual V1.01
www.simcom.com 17 / 77
must be below 0.4V.
The efficient input high level
must be higher than 1.0V.
After the PWRKEY continues
to pull down more than 15S,
the system will automatically
reset. Therefore, long-term
grounding is not
recommended
PWRKEY should never be
pulled down to GND
permanently.
RESET_N
45
DI,PU
Reset the module
V
ILmax
=0.4V
1.8V power domain. If
unused, keep this pin open.
SIM interface
USIM_DATA
14
I/O,PU
USIM Card data I/O, which
has been pulled up via a 20KR
resistor to USIM_VDD
internally. Do not pull it up or
down externally.
All lines of USIM interface
should be protected against
ESD.
USIM_RST
15
DO
USIM Reset
USIM_CLK
13
DO
USIM clock
USIM_VDD
16
PO
Power output for USIM card,
its output Voltage depends on
SIM card type automatically.
Its output current is up to
50mA.
USIM_PRESENC
E
44
DI
USIM card insertion detection
1.8V power domain. If
unused, keep this pin open.
USB
USB_VBUS
12
DI,PD
USB detection
V
IHmax
=1.8V
V
IHmin
=1.3V
Software download interface.
It is recommended to reserve
interfaces or test points.
USB_DP
11
I/O
Positive line of the differential,
bi-directional USB signal.
USB_DM
10
I/O
Negative line of the
differential, bi-directional USB
signal.
USB_VDDA_3P3
42
PI
Power for USB PHY circuit.
V
norm
=3.3V
USB_VDDA_3P3 and
EXT_PWR_EN pins are used
for USB PHY circuits.
EXT_PWR_EN
64
DO
USB_VDDA_3P3 voltage
enable signal.
1.8V power domain
UART interface
TXD
7
DOH
Transmit Data
1.8V power domain. If
unused, keep it open.
RXD
6
DI,PU
Receive Data
RTS
38
DI,PU
Request to send
CTS
39
DOH
Clear to Send
DCD
90
DOH
Carrier detects
DTR
62
DI,PU
DTE get ready
RI
76
DOH
Ring Indicator
DBG_TXD
60
DOH
Debug UART, the boot log will be
output during boot up.
1.8V power domain. If
unused, keep them open.
DBG_RXD
61
DI,PU
GNSS_UART_TXD
36
DOH
It can be configured as NMEA
1.8V power domain. If