ME310G1 Hardware Design Guide
1VV0301588 Rev. 16
Page 33 of 95
2021-10-27
Not Subject to NDA
Note: The PCB design must be well connected to the GND pads,
which is connected to a large copper surface.
Note: The Telit ME310G1 module includes a function to prevent
overheating.
4.3.3
Power Supply PCB Layout Guidelines
As seen in the electrical design guidelines, the power supply must have a low ESR
capacitor on the output to cut the current peaks on the input to protect the supply from
spikes. The positioning of this component is essential for the correct functioning of the
circuitry. A misplaced component can be useless or can even decrease the power supply
performance.
•
The low ESR Bypass capacitor must be placed near the Telit ME310G1 power
input pads or, if the power supply is of the switching type, it can be placed near
the inductor to cut the ripple, provided that the PCB trace from the capacitor
to the ME310G1 is wide enough to ensure a dropless connection even during a
2A current peak.
•
The protection diode must be placed close to the input connector where the
power source is drained.
•
The PCB
’s
traces to the ME310G1 and the Bypass capacitor must be wide
enough to ensure that no significant voltage drops occur. This is for the same
reason as in the previous point. Try to keep this trace as short as possible.
•
To reduce EMI due to switching, it is important to keep the mesh involved very
small; then the input capacitor, the output diode (if not incorporated into the
IC) and the regulator will form a very small loop. This is done to reduce the
radiated field (noise) to the switching frequency (usually 100-500 kHz).
•
A dedicated ground for the Switching regulator separated from the common
ground plane is suggested.
•
The placement of the power supply on the board must be done in such a way
as to guarantee that the high current return paths in the ground plane do not
overlap with noise-sensitive circuitry such as the microphone amplifier/buffer
or the earphone amplifier.
•
Power supply input cables should be kept separate from noise-sensitive lines
such as microphone/earphone cables.