Monitor The Power Supply; Power-On/Off Scenarios; Turn On Module Using The Pwrkey - Quectel EG91 Series Hardware Design

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].

3.7.1. Turn on Module Using the PWRKEY

The following table shows the pin definitionof PWRKEY.
Table 7: Pin Definition of PWRKEY
Pin Name Pin No.
PWRKEY 15
When EG91 is in powerdown 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 outputting a high level, PWRKEY pin can be released. A simple reference
circuit is illustrated in the following figure.
Another way to control the PWRKEY is using a button directly. When pressing the key, electrostatic strike
may generate from the finger. Therefore, aTVS component is indispensable to be placed nearby the
button for ESD protection. A reference circuit is shownin the following figure.
EG91_Hardware_Design

3.7. Power-on/off Scenarios

Description
Turn on/off the module
Figure 10: Turn on the Module Using Driving Circuit
DC Characteristics
V max=2.1V
IH
V min=1.3V
IH
V max=0.5V
IL
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LTE Module Series
EG91 Hardware Design
Comment
The output voltage is 0.8V
because of the diode drop in
the Qualcomm chipset.