User Guide

CCS Technical Documentation System Module and User Interface
Company confidential RH-23
Issue 1 02/2004 Nokia Corporation. Page 37
Internal Microphone
The internal microphone capsule is connected to main PWB. Microphone is omni direc-
tional and it’s connected to the UEM microphone input MIC1P/N. The microphone input
is asymmetric and the UEM (MICB1) provides bias voltage. The microphone input on the
UEM is ESD protected. Spring contacts are used to connect the microphone to the main
PWB.
Figure 19: Internal microphone connection
Table 35: Internal Microphone signal characteristics
Signal Min Nom Max Condition Note
MICP 200mVpp AC 2.2kohm to MIC1B
2.0V 2.1V 2.25V DC
MICN 2.0V 2.1V 2.25V DC
UEM
MIC1N
MIC1P
EMC
Microphone
MICB1