User's Manual

SIM7090G User Manual V1.01
www.simcom.com 27 / 77
Table 8: Power off timing and electronic characteristic
Symbol
Parameter
Time value
Unit
Min.
Typ.
Max.
T
off
The active low level time pulse on PWRKEY
pin to power off module
1.2
-
-
s
T
off(vdd)
The time from power-off issue to VDD_EXT pin
output low level
1.8
-
-
s
T
off(status)
The time from power-off issue to STATUS pin
output low level(indicating power off )*
1.8
-
-
s
T
off(uart)
The time from power-off issue to UART port off
1.8
-
-
s
T
off(usb)
The time from power-off issue to USB port off
1.8
-
-
s
T
off-on
The buffer time from power-off issue to
power-on issue
2
-
-
s
The STATUS pin can be used to detect whether module is powered on or not. When module has been
powered on and firmware goes ready, STATUS will be high level, or else STATUS will still low level.
3.2.3 Reset the Module
RESET_N is used to reset the module. The module can be reset by driving RESET_N to a low level voltage
for a period of time.
The RESET pin has been pulled up to 1.8V with a resistor internally. So it does not need to be pulled up
externally. It is strongly recommended to put an ESD protection diode close to the RESET pin. Please refer
to the following figure for the recommended reference circuit.
NOTE