Monitor The Power Supply; Turn On And Off Scenarios; Turn On Module Using The Pwrkey - Quectel UC20 Manual

3.6.4. Monitor the Power Supply

You can use the AT+CBC command to monitor the VBAT_BB voltage value. For more details, please
refer to document [1].

3.7. Turn on and off Scenarios

3.7.1. Turn on Module Using the PWRKEY

The following table shows the pin definition of PWRKEY.
Table 7: PWRKEY Pin Description
Pin Name Pin No.
PWRKEY 21
When UC20 is in power down mode, it can be turned on to normal mode by driving the PWRKEY pin to a
low level at least 100ms. It is recommended to use an open drain/collector driver to control the PWRKEY.
You can monitor the level of the STATUS pin to judge whether the module is turned on or not. 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.
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 showed in the following figure.
UC20_Hardware_Design
Description
Turn on/off the module.
≥ 100ms
4.7K
Turn on pulse
Figure 8: Turn on the Module Using Driving Circuit
DC Characteristics
V max = 2.1V
IH
V min = 1.3V
IH
V max = 500mV
IL
47K
Confidential / Released
UMTS/HSPA Module Series
UC20 Hardware Design
Comment
Pull-up to 1.8V internally
with 200kΩ resistor.
PWRKEY
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