Fig 11 Mechanical Layout And Interconnections Of Dct-4 Battery - Nokia RH-9 Series Ccs Technical Documentation

CCS Technical Documentation
2.7V
Hookint
/MBUS
EAD
Headint Headint
Mic_bias
MICB2
MIC2P
MIC2N
HF
3...25k
HFCM
UEM
Analog Audio Accessory Detection
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.
HeadInt comparator value is 1.9V. When the plug is inserted the switch in the connector
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.
Vice versa when the accessory is disconnected the HeadInt switch is closed and the
HeadInt is pulled down.
Basic Headset, fully differential
Button Headset (Switch closed)
Button Headset (Switch open)
PPH-1
No accessory
HeadInt signal is used to detect when the accessory is connected.
HookInt signal is used to detect when the button of the headset is pressed.
Note: Charging must be disabled during identification of PPH-1.
Headset Detection
Supported headsets are 4-wire fully differential accessories. Detection of the headset
can be split into five main phases:
Issue 1 11/02
Figure 12: Headset interface
Not all components are shown
1k0
2.1V
33N
33N
0.8V
0.8V
1k0
Table 28: Truth table for HookInt and HeadInt
ãNokia Corporation
1.8V
0.3V
HookInt
H
L
H
H
H
RH-9
System Module & UI
Button
Contact
MicGnd
HeadInt
H
H
H
H
L
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