Nokia 8390 서비스 매뉴얼

NSB-8

System Module & UI

PAMS Technical Documentation

Page 24

 

ãNokia Corporation

Issue 1 01/02

The internal clock frequency from UPP CTSI block is 13 MHz in GSM. Thus to achieve the
minimum starting SIMCardClk rate of 3.25 MHz (as is required by the authentication
procedure and the duty cycle requirement of between 40% and 60%) then the slowest
possible clock supplied to the SIM has to be in the GSM system clock rate of 13/4 MHz. 

Buzzer is used for generating alerting tones and melodies to indicate incoming call. It is
also used for generating warning tones for the user. Buzzer is controlled by PWM (Pulse
Width Modulation) signal generated by the buzzer driver of the UEM. Target SPL is 100dB
(A) at 5 cm.

The internal microphone capsule is situated in the bottom connector. Microphone is
omnidirectional. The internal microphone is connected to the UEM microphone input
MIC1P/N. The microphone input is asymmetric and microphone bias is provided by the
UEM MIC1B. The microphone input on the UEM is ESD protected. Spring contacts are
used for connecting the microphone to the main PWB.