Smart Module Series
SC690A_Series_Hardware_Design 40 / 105
3.2. Turn on
Table 8: Pin Definition of PWRKEY
The module can be turned on by driving the PWRKEY pin to a low level for at least 1.6 s. PWRKEY pin
is pulled to 1.8 V 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.
PWRKEY
> 1.6 s
MCU
GPIO
Module
Turn on pulse
R1
R2
Q1
Figure 7: Turn on the Module Using Driving Circuit
The other way to control the PWRKEY is by using a button directly. A TVS component is indispensable
to be placed nearby the button for ESD protection. A reference circuit is shown in the following figure.
PWRKEY
Module
S1
Close to S1
TVS
Turn-on pulse
1 K
Figure 8: Turn on the Module Using Keystroke
Pin Name
Pin No.
I/O
Description
Comment
PWRKEY
39
DI
Turn on/off the module
Pull up to 1.8 V internally.
Active low.