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N720 OpenLinux
Hardware User Guide
Copyright © Neoway Technology Co., Ltd
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recommended) into PWRKEY_N to start the module. The PWRKEY_N pin is internally connected to
the power supply through a 200 kΩ pull-up resistor. Do not connect an external resistor with large
resistance. Otherwise, the module cannot be powered up since the PWRKEY_N is input high level all
the time internally.
If the application do not have to control the ON/OFF state of the module, connect PWRKEY_N to the
ground through a 1.5 kΩ pull-down resistor. Then, the module can start automatically once it is powered
up.
Do not perform other operations on the module until it is initialized completely. If the module is powered
up but the startup process has not been completed, the states of each pin are uncertain.
Shutdown Process
The module can be powered off in two ways: hardware power off and software power off.
PWRKEY_N is used to hardware power off the module. When the module is working, inputting negative
pulses for more than 2 seconds to PWRKEY_N can trigger the power-off state of the module.
If you use a 2.8V/3.3V IO system, it is recommended to add a triode to separate it. For details, refer to
3.2.2 RESET_N.
For how to power off through software, see
Neoway_N720 OpenLinux_AT_Command_Manual
.
Figure 3-9 N720 on/off timing
VBAT
RESET_N
t >200ms
V
L
<0.6V
USB
t >2s
Inactive
Active
Inactive
Inactive
Active
Inactive
All Interfaces
PWRKEY_N
V
L
<0.6V
Inactive
Active
Inactive
Power
ON
Power
OFF
Time