LTE Standard Module Series
EC25 Hardware Design
EC25_Hardware_Design 43 / 130
3.7. Power-on/off Scenarios
3.7.1. Turn on Module Using the PWRKEY
The following table shows the pin definition of PWRKEY.
Table 7: Pin Definition of PWRKEY
When EC25 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 500ms. It is recommended to use an open drain/collector driver to control the
PWRKEY. After STATUS pin (require external pull-up resistor) outputs a low level, PWRKEY pin can be
released. A simple reference circuit is illustrated in the following figure.
PWRKEY
4.7K
47K
≥ 500ms
10nF
Turn-on pulse
Figure 10: Turn on the Module by Using Driving Circuit
The other way to control the PWRKEY is using a button directly. When pressing the key, electrostatic
strike may generate from finger. Therefore, a TVS component is indispensable to be placed nearby the
button for ESD protection. A reference circuit is shown in the following figure.
Pin Name Pin No. I/O Description Comment
PWRKEY 21 DI Turn on/off the module
The output voltage is 0.8V because of
the diode drop in the Qualcomm chipset.
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