User's Manual

GE864- QUAD Har dwar e User Guide
1vv0300872 Rev.1 2010-04-02
- All Rights Reserved. Page 48 of 77
1.2 Electr ical Char acter istics
TIP: Being the microphone circuitr y the more noise sensitive, its design and layout
must be done with particular care. Both micr ophone paths are balanced and the OEM
circuitr y must be balanced designed to reduce the common mode noise typically
gener ated on the ground plane. However the customer can use the unbalanced
circuitr y for particular application.
10.1.1. Input Lines Characteristics
differential m icr ophone paths
Line Coupling
AC*
Line Type
Balanced
Coupling capacitor
≥ 100nF
Differential input resistance
50kΩ
Differential input voltage
≤ 1,03V
pp
@ MicG=0dB
(* ) WARNING : AC means that the signals from the microphone have to be
connected to input lines of the module through capacitors which value has to
be ≥ 100nf. not respecting this constraint, the input stages will be damaged.
WARNING: when particular OEM application needs a Single Ended Input
configur ation, it is for bidden connecting the unused input directly to Ground,
but only thr ough a 100nF capacitor. in Single Ended configuration
the useful input signal will be halved.