LPM2100 mg NB Module Hardware User Guide
Shanghai Yuge Information Technology Co., Ltd.
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①
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.
②
It is recommended to add multiple different capacitance capacitors (10pF, 1uF,
100nF, 100uF) to the VBAT pin and place them near the VBAT pin.
3.3.2 VDD_EXT Voltage output
After the LPM2100 mg series module is powered on normally, the 24th pin will output
the IO voltage domain, and the current load can be up to 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.
Figure 3-3 VDD_EXT power output timing diagram
3.4 Switching machine reset mode
3.4.1 Boot
When the LPM2100 mg series module is turned off, it can be turned on by pulling
PWRKEY low on pin 7 for at least 800ms. It is recommended to use the open collector drive
circuit to control the PWRKEY pin. The reference circuit is as follows.
Figure 3-4 Boot reference circuit
The following picture shows the boot timing diagram
：
