User's Manual

LTE Module Series
EC21 Hardware Design
EC21_Hardware_Design Confidential / Released 36 / 94
Figure 11: Turn on the Module Using Keystroke
The turn on scenario is illustrated in the following figure.
Figure 12: Timing of Turning on Module
Please make sure that VBAT is stable before pulling down PWRKEY pin. The time between them is no
less than 30ms.
NOTE