LPM2100 bg NB Module Hardware Usage Guide
Shanghai Yuge Information Technology Co., Ltd.
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3.3 Power interface
The LPM2100 bg series module power connector consists of two parts
:
VBAT is the working power of the module;
VDD_EXT is the internal LDO output IO voltage domain (current load up to 50mA) for
external use.
3.3.1 VBAT interface
The power supply VBAT has a power-on voltage range of 3.1~4.2V(Low voltage version:
2.45~4.2V). The module powers the internal RF and baseband circuitry through the VBAT pin.
Under the premise of ensuring that the VBAT power supply is sufficient, it is recommended to
be close to the power input and put 10pF, 0.1uF,1uF ceramic capacitor and 100uF tantalum
capacitor. VBAT PCB traces are as short and thick as possible
。
Figure 3-2 VBAT power supply
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 bg series module is powered on normally, the 26th 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.