User's Manual

LE910 Hardware User Guide
1vv0301089 Rev.3 – 09-06-2014
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 35 of 79
 The use of a good common ground plane is suggested.
 The placement of the power supply on the board should be done in such a way to
guarantee that the high current return paths in the ground plane are not overlapped
to any noise sensitive circuitry as the microphone amplifier/buffer or earphone
amplifier.
 The power supply input cables should be kept separate from noise sensitive lines
such as microphone/earphone cables.
 The insertion of EMI filter on VBATT pins is suggested in those designs where
antenna is placed close to battery or supply lines.
A ferrite bead like Murata BLM18EG101TN1 or Taiyo Yuden P/N
FBMH1608HM101 can be used for this purpose.
The below figure shows the recommended circuit: