Smart LTE Module Series
SC66 Hardware Design
SC66_Hardware_Design 45 / 139
3.5. Turn on and off Scenarios
3.5.1. Turn on the Module Using PWRKEY
The module can be turned on by driving PWRKEY pin to a low level for at least 3ms. PWRKEY pin is
pulled to 1.8V internally. It is recommended to use an open drain/collector driver to control the PWRKEY.
A simple reference circuit is illustrated in the following figure.
Turn on pulse
PWRKEY
4.7K
47K
>3ms
R1
R2
Q1
R3
1K
Figure 6: Turn on the Module Using Driving Circuit
Another way to control the PWRKEY is using a button directly. For ESD protection, A TVS component
pla
ced near the button and a 1kΩ resistor connected to the PWRKEY in series are indispensable. A
reference circuit is shown in the following figure:
PWRKEY
S1
Close to S1
TVS
1K
Figure 7: Turn on the Module Using Keystroke