Audio Circuitry - Nokia RH-6 Series Baseband Description & Troubleshooting

RH-6
6 - BB Description & Troubleshooting
TRANSCEIVER
0R22
10n 1u
Connecting a charger to the telephone creates a voltage, VCH, on the UEM VCHAR input.
When the VCH level is detected to rise above the VCH
charging starts.
3-wire chargers can be connected, but the PWM is not supported.
In order to protect the phone from damage due to over voltage caused by a sudden bat-
tery removal while charging proceeds, the charger switch is closed immediately.

Audio circuitry

This section describes the audio-HW inside the BB. Thus e.g. external audio components
and acoustics are not considered with the details in this section.
The main topology comes from other phones using BB4.0 engine, where the audio-HW is
mostly integrated into the UEM-ASIC. The biggest difference is that Maxwell has also
integrated hands-free (IHF).
Page 16
Company Confidential
UEM
VCHAROUT VCHARIN
VBATREGS
CHACON
PWM
Figure 4: Charging configuration
© 2003 Nokia Corporation.
CCS Technical Documentation
42R/100MHz
1.5A
1n
threshold (2.0 Vdc) by CHACON,
DET
CHARGER
VCHAR
GND
Issue 1 10/2003