Lcd & Keyboard Backlight - Nokia RH-9 Series Ccs Technical Documentation

CCS Technical Documentation
This A/D channel has a feature built into it that the charger voltage measurement can be
specified to be performed when the charger switch is closed or open. This information is
provided by the MCU when this channel is addressed.
The charger measurement A/D channel can also be timed to the charger envelop detector
in order to measure the standard charger peak voltage.
Charger Current Measurement A/D Channel (
This A/D channel is used to measure the charger current ICHAR. The current sensor is
implemented using 0.22 Ω resistor in series between UEM charging voltage output and
battery voltage. The voltage drop over the resistor is examined. The charger current mea-
surement is used for charger detection and maintenance charging PWM calculations.
Battery Temperature Measurement A/D Channel (
The temperature of the battery pack is monitored during charging. The battery pack is
equipped with an NTC resistor, value is 47kOhm at 25
on the baseband to the UEM. An external 100kOhm pull-up is needed.
Battery Size Measurement A/D Channel (
This channel is used to identify the battery. The battery pack BLC-2 has a resistor
75kOhm connected to ground. An external 100kOhm pull-up resistor is on the phone
side. The BSI signal is connected to UEM.
External Accessory Detection A/D Channel (
In order to be able to detect DCT4 type of accessories an A/D converter channel is used to
measure the DC level on the external microphone. The detection is implemented using a
pull-down resistor in the accessory and a pull-up on the baseband side. The pull-up
resistor on the baseband side is internal to the UEM. This A/D channel is internally con-
nected to either HeadInt or HookInt.
PA Temperature measurement A/D Channel (
In RH-9 this A/D channel is used for Cover Type Detection (CTI) in conjunction with DC-
OUT covers.The detection is implemented using a pull-down resistor in the accessory and
a pull-up on the baseband side.
LCD & Keyboard Backlight
LCD Backlight
LCD Backlight consists of 2 TBSF (Through the Board Side Firing) white LEDs which are
placed on the main PWB below the LCD area. They lit into the light guide where the light
is distributed to generate sufficient backlight for the LCD.
Issue 1 11/02
ICHAR)
BSI)
HEADINT, HOOKINT)
PATEMP)
ãNokia Corporation
System Module & UI
BTEMP)
o
C. The BTEMP signal is connected
RH-9
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