Power Supply Monitoring - Quectel BG95 A-GL Series Hardware Design

LPWA Module Series
To decrease voltage drop, one bypass capacitor of about 100 μF with low ESR and one multi-layer
ceramic chip (MLCC) capacitor array for its ultra-low ESR should be used for VBAT_BB & RF respectively.
It is recommended to use three ceramic capacitors for composing the MLCC array (100 nF, 33 pF, 10 pF),
and place these capacitors close to VBAT pins. The main power supply from an external application must
be a single voltage source that can supply power along two star-structured sub paths. The width of
VBAT_BB or VBAT_RF trace should be at least 1 mm. In principle, the longer the VBAT trace is, the wider
it should be.
In addition, to ensure power supply stability, it is necessary to add two high-power TVS components near
VBAT_BB and VBAT_RF. The reference circuit of the power supply is shown below.
Figure 10: Star Structure of Power Supply
Power design for the module is critical to its performance. For BG950A-GL/BG951A-GL/BG953A-GL, 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. For BG955A-GL, the power supply design is
to be confirmed.

3.7.3. Power Supply Monitoring

AT+CBC can be used to monitor the VBAT_BB voltage value. For more details, see document [3].
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