Fibocom MG661-EU - Power Input

3 Application Interfaces
25
Indicator
Minimum
Value
Maximum
Value
Unit
GPIO
Level power supply
voltage of digital I/O
–0.3
2.0
V
3.1.2 Power Input
Background
The performance of the power supply such as its load capacity, ripple etc. will directly affect
the operating performance and stability of the module. If the power supply capacity is
insufficient and the power supply voltage instantaneous drops, the module may be powered
off or restarted.
The following figure shows the power supply limit.
Burst transmit Burst transmit
min:3.4V
Power supply
Ripple  300mV
Drop
VBAT  3.4V
Figure 3. Power supply limit
The ripple of the power supply should be lower than 300 mV, and the line ESR (equivalent
series resistance) should be < 150 mΩ. When the module is working, it is necessary to ensure
that the DC power supply voltage is between 3.4V and 4.5V, including voltage sag, ripple and
spike. The module power supply is far away from interference sources such as antennas.
Schematic Diagram Design
VBAT is the power pin of the module.