User's Manual

CE910 Family Hardware User Guide
1vv0301010 Rev.11 – 2015-10-27
Reproduction forbidden without written authorization from Telit Communications S.p.A. - All Rights Reserved.
Page 49 of 75
9.1.2. LIN-IN Connection
If the audio source is not a mike but a different device, the following connections can be done. Place
100nF capacitor in series with both inputs, so the DC current is blocked. Place the 33pF-100Ohm-
33pF RF-filter, in order to prevent some EMI field to get into the high impedance high gain MIC
inputs. Since the input is differential, the common mode voltage noise between the two (different)
grounds is rejected, provided that both AF_IN+ & AF_IN- are connected directly onto the source.