Charge Control; Audio - Nokia RH-27 Series Technical Documentation Manual

RH-27
Troubleshooting - Baseband
X102
F100
2
1.5A
1

Charge Control

In active mode, charging is controlled by UEM's digital part. Charging voltage and cur-
rent monitoring is used to limit charging into safe area. For that reason, UEM has pro-
grammable charging cut-off limits:
VBATLim1=3.6 V (Default)
VBATLim2L=5.0 V and
VBATLim2H=5.25 V.
VBATLim1, 2L, 2H are designed with hystereses. When the voltage rises above VBATLim1,
2L, 2H+ charging is stopped by turning charging switch OFF. No change in operational
mode is done. After voltage has decreased below VBATLim- charging re-starts.
There are two PWM frequencies in use depending on the type of the charger: two-wire
charger uses a 1Hz and a three-wire charger uses a 32Hz. Duty cycle range is 0% to
100%. Maximum charging current is limited to 1.2 A.
UEM Pins
N10
M10

Audio

The audio control and processing in RH-27 is supported by UEM, which contains the
audio codec, and UPP, which contains the MCU and DSP blocks, handling and processing
the audio data signals.
The baseband supports three microphone inputs and two earpiece outputs. The micro-
phone inputs are MIC1, MIC2, and MIC3. MIC1 input is used for the phone's internal
Page 20
L100
________
42R/100MHz
Figure 7: Charging circuit
R200
.22 Ohms
Figure 8: Charging circuit at battery
©2003 Nokia Corporation
CCS Technical Documentation
"VCHARIN"
C106
V100
1n0
C237 C202
1uF 10nF
Confidential
0
C110
2
22p
CHARGER(4:0)
VBAT
Issue 1 11/2003