CLM920_AC3 Module Hardware Usage Guide
Shanghai Yuge Information Technology co., LTD
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3.3.3 VDD_EXT Voltage output
The CLM920 AC3 module outputs 1.8V through VDD_EXT for internal digital circuitry.
This voltage is the logic level voltage of the module. After normal power-on, the 17th pin will
output 1.8V and the current load will be 50mA. The external master can read the voltage of
VDD_EXT to determine if the module is powered on. VDD_EXT can also be used as an
external power supply, such as a level shifting chip.
3.4 Switching machine reset mode
3.4.1 Module boot
The 21 pin of the CLM920 AC3 module is the boot pin. The module can be powered
down by PWRKEY for at least 500ms. The user can check whether the module is powered on
by querying the high and low levels of the VDD_EXT pin.
When the CLM920 AC3 module is powered on, pull the PWRKEY pin low for at least 1S
and release it. The module will perform shutdown process shutdown (this function is under
development).
Table 3-5 Switching machine pin definition
Pin
Name
I/O
High value
Description
21
PWRKEY
PI
VBAT-0.3V
Active low
