User's Manual

UE910 V2 Hardware User Guide

1VV0301065 Rev.1 – 2013-12-12

TIP: Since the J-FET transistor inside the microphone acts as RF-detector-amplifier, ask vendor for a

microphone with anti-EMI capacitor (usually a 33pF or a 10pF capacitor placed across the output

terminals inside the case).

9.1.2. LIN-IN Connection (TBD)

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.