Nokia 3105 Servicehandbuch

CCS Technical Documentation

System Module

RH-48

Issue 1 11/2003      Confidential         ©

2003 Nokia Corporation

Page 15

An accessory is detected by the ACI-line. All accessories will generate interrupt while 
inserted or removed from the phones Tomahawk system connector. Insertion of an acces-
sory will generate HEADINT interrupt by pulling ACI line down.  Vout is enabled by UPP.  
The MBUS line is connected to HEADINT line.  If HEADINT interrupt from low to high 
transition occurs within 20msec a more advanced accessory is connected else a basic 
headset is connected.

Introduction

The charger connection is implemented through the bottom connector. DCT-4 bottom 
connector supports charging with both plug chargers and desktop stand chargers.

There are three signals for charging. Charger gnd pin is used for both desktop and for 
plug chargers as well as charger voltage. PWM control line, which is needed for 3-wire 
chargers, is connected directly to gnd in module PWB so the RH-48 engine doesn't pro-
vide any PWM control to chargers. Charging controlling is done inside UEM by switching 
UEM internal charger switch on/off.

Interface

The fuse (F100) protects from high currents (e.g. , when broken or pirate chargers are 
used). L100 protects engine from RF noises that may occur in charging cable. V100 pro-
tects UEM ASIC from reverse-polarity charging and from high charging voltage.  C106 is 
also used for ESD and EMC protection. 

 

5.70

 

3.50

XM

IC

 N

 

XM

IC

 P

 

AC

I

 

21.20

V

out

 

6.55

 

US

B

 Vbus

 

  

 U

S

B D-

 / 

Fbus

 T

X

 

US

B D+

 /

 F

b

u

s RX

 

DAT

A

 GN

D

 

2.70

 

1.00

S

h

ie

ld

ing GND

 

HSE

A

R

 P

 

HSE

A

R

 N

 

5.40

 

0.30

Metal 
shielding

 

Shielding GN

D

 

HS

EAR R

 P

 

H

S

E

A

R R N

 

9.50

 

6.50

 

Ch

ar

g

e GN

D