User Guide

NPM-6/6X
System Module and User Interface CCS Technical Documentation
Page 32 Nokia Corporation. Issue 2 06/03
External Accessory Regulator
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
Figure 7: External Accessory regulation
External Audio
NPM-6/6X is designed to support fully differential external audio accessory connection.
A headset can be directly connected to the system connector. With NPM-6/6X, two dif-
ferent kinds of headsets can be used; Stereo and Mono headset. Headset is also used as
antenna input for the FM radio.
Headset implementation uses separate microphone and earpiece signals. The accessory is
detected by the HeadInt signal when the plug is inserted. Normally when no plug is
present the internal pull-down on the HF pin pulls down the HeadInt signal.
Due to the that the comparator level is 1.9V the HeadInt signal will not change state
even if the HF output is biased to 0.8V. When the plug is inserted the switch is opened
and the HeadInt signal is pulled up by the internal pull-up. The 1.9V threshold level is
reached and the comparator output changes to low state causing an interrupt.
The hook signal is generated by creating a short circuit between the headset microphone
signals. When no accessory is present, the HookInt signal is pulled up by the UEM resis-
tor.
Signal Min. Nom Max Note
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
UPP
Genio(0)
VBAT
Vout
System Connector