User's Manual

LTE Module
EC20 Hardware Design
EC20_Hardware_Design Confidential / Released 30 / 83
When EC20 is in power down mode, it can be turned on to normal mode by driving the PWRKEY pin to a
low level for at least 100ms. It is recommended to use an open drain/collector driver to control the
PWRKEY. After STATUS pin (require external pull-up) outputting a low level, PWRKEY pin can be
released. A simple reference circuit is illustrated in the following figure.
Turn on pulse
PWRKEY
4.7K
47K
≥ 100ms
Figure 10: Turn on the Module Using Driving Circuit
The other way to control the PWRKEY is using a button directly. A TVS component is indispensable to be
placed nearby the button for ESD protection. When pressing the key, electrostatic strike may generate
from finger. A reference circuit is shown in the following figure.
PWRKEY
S1
Close to S1
TVS
Figure 11: Turn on the Module Using Keystroke