Cavli Wireless C100QM/C10QM Hardware Manual
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To prevent damage to the module from surges and overvoltages, it is recommended
to connect a 5.1V/500mW Zener diode to the VBAT pin of the module.
✧
It is recommended to add 3 ceramic capacitors (33pF, 10pF, 100nF) to the VBAT pin
and place them near the VBAT pin.
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The minimum operating voltage of the module is 3.3V. Since the transmission data or
GSM call will generate more than 2A current, the ripple voltage drop will occur on the
power supply voltage, so the actual supply voltage must not be lower than 3.3V.
3.3.3 VDD_SDIO 1.8V/2.85V voltage output
The module output VDD_SDIO is configurable at 2.85V/1.8V. The default is 2.85V
and the maximum output current is 50mA. It can only be used for SDIO bus pull-up. The
SD card power supply needs to be provided from outside the module.
3.3.4 VDD_EXT 1V8 voltage output
After the C100QM/C10QM module is powered on normally, 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 judge whether 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 Boot
The 21 pin of the C100QM/C10QM module is the boot pin. The module is powered on at
low level. The PWRKEY is pulled low for at least 500ms. When the module is powered on,
the user can check whether the module is powered on by querying the high and low levels
of the VDD_EXT pin.
When the C100QM/C10QM module is powered on, pull the PWRKEY pin low for at
least 1S and release it. The module will perform the shutdown process shutdown (this
function is under development).