Smart Module Series
SA800U-WF Hardware Design
SA800U-WF_Hardware_Design 41 / 106
Another way to control PWRKEY is using a button directly. A TVS component should be placed nearby
the button for ESD protection. A reference circuit is shown in the following figure.
PWRKEY
S1
Close to S1
TVS
1K
Figure 7: Turn on the Module Using Keystroke
The timing of turning on is illustrated in the following figure.
VBAT (Typ. 3.8 V)
PWRKEY
> 1.6 s
Others
VREG_S4A_1V8
30 s
SD_LDO13A
40.7 ms
Software
controlled
LDO24A_3V075
Active
LDO12A_1V8
Note2
Software
controlled
Figure 8: Timing of Turning on the Module