Microphone - Nokia RH-18 Manual

RH-18/36/38
Engine module
Two dust shields will be used: one in the gap between earmat and A-cover and one on
the C-cover.
The earpiece circuit includes only a few components:
UEM
EARP
EARN

Microphone

An omni directional microphone is used. The microphone is placed in the system connec-
tor sealed in its rubber gasket. The sound port is provided in the system connector.
The microphone connection comprises a differential bias circuit, driven directly from the
MICB1 bias output with external RC-filters.
Page 20
Company confidential
two 10 ohm in order to have a stable output
an EMC filter
Placed in top of
Placed near UEM
10
ohm
10
ohm
Figure 4: Earpiece interface
Figure 5: Bottom connector including the microphone
Nokia Corporation.
CCS Technical Documentation
PWB, near
earpiece
EARP
EARN
Issue 1 10/03