LPWA Module Series
BG952A-GL_QuecOpen_Hardware_Design
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recommended to use three ceramic capacitors (100 nF, 33 pF, 10 pF) for composing the MLCC array,
and place these capacitors close to VBAT pins. The main power supply from an external application has
to be a single voltage source and can be expanded to two sub paths with star structure. The width of
VBAT_BB trace should be no less than 0.6 mm, and the width of VBAT_RF trace should be no less than
2 mm. In principle, the longer the VBAT trace is, the wider it should be.
In addition, to get a stable power source, it is suggested to use two TVSs with low leakage current and
suitable reverse stand-off voltage, and also it is recommended to place them as close to the VBAT pins as
possible. The following figure shows the star structure of the power supply.
Figure 4: Star Structure of the Power Supply
Power design for a module is critical to its performance. The power supply of the module should be able
to provide a sufficient current of at least 0.8 A, so it is recommended to select a DC-DC converter chip or
an LDO chip with ultra-low leakage current and current output of at least 1.0 A for the power supply
design.
3.7.3. Power Supply Monitoring
AT+CBC
can be used to monitor the VBAT_BB voltage value. For more details, see
document [3]
.
3.8. Turn on
3.8.1. Turn on Module with PWRKEY
The following table shows the pin definition of PWRKEY.
