UMTS/HSPA+ Module Series
UG89 Hardware Design
UG89_Hardware_Design 28 / 73
3.6.2.1. Turn off the Module Using the PWRKEY Pin
Driving the PWRKEY pin to a low-level voltage for at least 650ms, the module will execute power-down
procedure after the PWRKEY is released. The timing of turning off the module is illustrated in the following
figure.
VBAT
PWRKEY
≥
2s
≥
650ms
RUNNING
Power-down procedure
OFF
Module
Status
STATUS
(DO)
Figure 9: Timing of Turning off the Module
3.6.2.2. Turn off Module Using AT Command
It is also a safe way to use
AT+QPOWD
command to turn off the module, which is similar to the procedure
of turning off the module via PWRKEY pin.
Please refer to
document [2]
for details about
AT+QPOWD
command.
1. In order to avoid damaging internal flash, please do not switch off the power supply when the
module works normally. Only after the module is shut down by PWRKEY or AT command, the
power supply can be cut off.
2. When turning off the module with the AT command, please keep PWRKEY at a high level after the
execution of the command. Otherwise, the module will turn itself back on after being shut down.
3.6.3. Reset the Module
The RESET_N pin can be used to reset the module. The module can be reset by pulling the RESET_N
pin low for at least 300ms and then releasing it. The RESET_N signal is sensitive to interference, so it is
recommended that the traces between the RESET_N pin and
customers’ device should be as short as
NOTES
