Nokia 6610i Service Manual

CCS Technical Documentation

7-System Module and User Interface

                                 

Company confidential 

RM-37

Issue 1  04/2004

  ©Nokia Corporation.

Page 35

An external LDO Regulator exists for accessory power supply purposes. All ACI-accesso-
ries require this power supply. Regulator input is connected to battery voltage VBAT and 
output is connected to Vout pin in the system connector. Regulator is controlled via UPP 
(On/Off-function).

Accessory Regulator Signals  

RM-37 is designed to support fully differential external audio accessory connection by 
using Pop-Port [TM] system connector. Pop-Port [TM] connector has serial data bus 
called ACI (Accessory Control Interface) for accessory insertion and removal detection 
and identification and authentication. ACI line is also used for accessory control pur-
poses. See section ACI, Accessory Control Interface. Audio support from Pop-Port [TM] 
system connector:

4-wire fully differential stereo audio (used also FM-radio antenna connection)

2-wire differential mic input

The external microphone input is fully differential and lines are connected to the UEM 
microphone input MIC2P/N. The UEM (MICB2) provides bias voltage. Microphone input 
lines are ESD protected.

Creating a short circuit between the headset microphone signals generates the hook sig-
nal. When the accessory is not connected, the UEM resistor pulls up the HookInt signal. 
When the accessory is inserted and the microphone path is biased the HookInt signal 
decreases to 1.8V due to the microphone bias current flowing through the resistor. When 
the button is pressed the microphone signals are connected together, and the HookInt 
input will get half of micbias dc value 1.1 V. This change in DC level will cause the Hook-

Vout

2.70V

2.78

2.86V

I

max

 = 150mA

GenIO(0)

1.4

1.8

1.88
0.6

High (ON)
Low (OFF)

Accessory 
Regulator 

Genio(0) 

VBAT 

Vout  

 

System Connector