Users Manual

LTE Standard Module Series
EC25 Hardware Design
EC25_Hardware_Design
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Figure 9: Reference Circuit of Power Supply
In order to avoid damaging internal flash, please do not switch off the power supply when the module
works normally. Only after the module is shut down by PWRKEY or AT command, then the power supply
can be cut off.
3.6.4. Monitor the Power Supply
AT+CBC command can be used to monitor the VBAT_BB voltage value. For more details, please refer to
document [2].
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.
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.
NOTE