Specifications

SIM7912&SIM7906 Hardware Design V1.02
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3.2.2 Power Off
The following methods can be used to power off the module.
● Method 1: Power off the module by holding the PWRKEY to a low level 2 second then release.
● Method 2: Power off the module by AT command “AT+CPOF”.
For details about “AT+CPOF”, please refer to Document [1] in the appendix.
If the temperature is outside the range of -30~+70℃, some warning will be reported via AT port. If the
temperature is outside the range of -40~+85℃, module will be powered off automatically.
For details about “AT+CPOF”, please refer to Document [1] in the appendix.
Normal power off action will make the module disconnect from the network, allow the software enter a safe
state, and save key data before the module is powered off completely.
The power off sequence is shown in the following figure.
( Input)
USB Port
Inactive
Active
PWRKEY
Active
STATUS
T
off (STATUS)
VDD_EXT
T
off(VDD_EXT)
T
off(USB)
T
off
Figure 11: Power off sequence
Table 11: Power off timing and electronic characteristic
Symbol
Parameter
Time value
Unit
Min.
Typ.
Max.
T
off
The time of holding on PWRKEY pin to a low level
2.5
-
5
s
T
off(usb)
The time from power-off issue to USB port off
27
28
-
s
T
off(status)
The time from power-off issue to STATUS off
25
26
-
s
NOTE
NOTE