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LTE-A Module Series
EG18 Hardware Design
EG18_Hardware_Design 40 / 104
Another way to control the PWRKEY is using a button. Electrostatic strike may generate from fingers
when the button is pressed. Therefore, it is necessary to place a TVS component nearby the button for
ESD protection. A reference circuit is shown by the following figure:
PWRKEY
S1
Close to S1
TVS
Figure 12: Turn on the Module Using a Button
The timing of turn-on scenario is illustrated by the following figure.
V
IL
≤0.5V
V
IH
≥1.3V
VBAT
PWRKEY
≥500ms
RESET_N
STATUS
Inactive
Active
UART
NOTE
≥11.5s
≥13s
VDD_EXT
VDD_RF
≥17s
≥100ms
USIM_VDD
≥16s
≥29ms
Figure 13: Timing of Turning on the Module
Please ensure that VBAT is stable for no less than 30ms before pulling down the PWRKEY.
NOTE