Power Off Sequence - SIM Tech SimCom SIM7100 Hardware Design

Table 8: Power on timing and Electronic Characteristic
Symbol
The time of active low level impulse on PWRKEY
T
on
pin to power on module
The time from power-on issue to STATUS pin
T
on(status)
output high level(indicating power up ready )
T The time from power-on issue to UART port ready
on(uart)
V Input high level voltage of PWRKEY pin
IH
V Input low level voltage of PWRKEY pin
IL
3.2.2

Power off Sequence

The following methods can be used to power down SIM7100. These procedures will make module
disconnect from the network and allow the software to enter a safe state, and then save data before
completely powering the module off.
Method 1: Power off SIM7100 by pulling the PWRKEY pin down
●
Method 2: Power off SIM7100 by AT command
●
Method 3: over-voltage or under-voltage automatic power down.
●
Method 4: over-temperature or under-temperature automatic power down.
●
User can power off the SIM7100 by pulling PWRKEY down to ground for a specific time. The power off
scenario is illustrated in the following figure.
PWRKEY
( Input )
STATUS
( Output )
UART Port
SIM7100_Hardware Design_V1.01
Parameter
AT+CPOF
"
T
off
T
Active
Figure 13: Power off timing sequence
29
Smart Machine Smart Decision
Time value
Min. Typ.
100 500
10
10
1.17 1.8
-0.3 0
"
off(status)
T
off(uart)
Undefined
Unit
Max.
- ms
- -
s
- - s
2.1 V
0.3 V
T
off-on
T
on
2015-01-20