Smart Module Series
SC606T Series Hardware Design
SC606T_Series_Hardware_Design 40 / 116
Another way to control PWRKEY is with a button. A Transient Voltage Suppressor (TVS) should be
placed nearby the button for ESD protection. A reference design is shown in the following figure.
PWRKEY
S1
Close to S1
TVS
1K
Figure 7: Turn On Module Using Button
The timing of turning on the module is illustrated in the following figure.
VBAT (Typ.3.8 V)
PWRKEY
> 1.6 s
Others
LDO5_1P8
38 s
LDO6_1P8
61.2 ms
Software
controlled
LDO17_2P85
Active
LDO10_2P8
Note2
Software
controlled
Figure 8: Power-up Timing
1. When the module powers on for the first time, the power-up timing might be different from what is
shown in the figure above.
2. Ensure that VBAT is stable for at least 30 ms before pulling down the PWRKEY pin.
NOTES