User's Manual

Smart Machine Smart Decision
SIM7020G_User Manual_V1.00 24 2019-01-15
Table 10: Power on timing and electronic characteristic
Symbol
Parameter
Min.
Typ.
Max.
Unit
T
on
The time of active low level impulse of
PWRKEY pin to power on module
215
800
-
ms
T
on(status)
The time from power-on issue to
STATUS pin output high level(indicating
power up ready )
440
ms
T
on(uart)
The time from power-on issue to UART
port ready
2
s
T
on(usb)
The time from power-on issue to USB
port ready
4
s
V
IH
Input high level voltage on PWRKEY pin
0.7*VBAT
V
V
IL
Input low level voltage on PWRKEY pin
0.3*VBAT
V
3.4.2 Power off
The following methods can be used to power off SIM7020G.
➢ Method 1: Power off SIM7020G by pulling the PWRKEY pin to ground.
➢ Method 2: Power off SIM7020G by AT command “AT+CPOWD=1”.
➢ Method 3: over-voltage or under-voltage automatic power off. The function can be enabled by
AT command “AT+CBATCHK=1”. Default is disabled.
Note: For details about “AT+CPOWD” and “AT+CBATCHK”, please refer to Document [1].
These procedures will make modules disconnect from the network and allow the software to enter a
safe state, and save data before module be powered off completely.
The power off scenario by pulling down the PWRKEY pin is illustrated in the following figure.
(
Output
)
T
off
( Input
)
T
off(status)
UART Port
UndefinedActive
T
off(uart)
T
on
T
off-on
USB Port
Undefined
Active
T
off(usb)
PWRKEY
STATUS
Figure 10: Power off timing sequence