Baseband Electrical Interfaces: Battery; Baseband Electrical Interfaces: Charger - Nokia RM-761 Service Manual

RM-761; RM-799; RM-800
System Module
Quantum supports dual or single speaker configuration. Single speaker configuration is used when having
either just a single speaker for both IHF and normal handset operation, or when using a multi-actuator or 3-
in-1-device with integrated vibrator functionality. For single speaker configurations 3.9 Ohm serial resistors
must be inserted in the earpiece driver outputs as indicated in the above figure to isolate the driver from
the low speaker impedance.
The X-GOLD213 has an integrated Class D power amplifier (LSP/LSN) that can drive an 8ohm load at the
maximum rating of 700 mW rms (at VBATmax). The Class D amplifier is supplied directly by the phone battery
and therefore the driving capability depends on the battery voltage.
The default switching frequency of the amplifier is initially set to approximately 600kHz, but may be varied
between 400kHz to 800kHz in the case of harmonic interference to the GSM RF frequencies or FM radio receive
channel. External ferrite beads L3100 and L3000 have been added on the amplifier outputs to minimize
interference.
Figure 56 Speaker outputs with ferrite filters

Baseband electrical interfaces: Battery

X2080 is battery connector, battery supply voltage range is 3.2V to 4.2V. The middle pin of the connector is
for battery ID, the BSI resistor value should be 68K (default value, normal mode without charging) or 3.3K
(test mode), the nominal resistance of actual NTC resistor is 47K at room temperature.

Baseband electrical interfaces: Charger

Charge voltage is detected by an external voltage divider. The voltage (VCHG) is measured by a 10-bit PMU
ADC with a dynamic range from 0 to 1.2V. The maximum ADC voltage corresponds to 32.4V with the current
external divider ratio hence the resolution is 31.6mV/LSB.
In order to validate the charge voltage, an upper and a lower limit are programmed in the PMU charger
control registers. These registers can be programmed by SW during run-time. During HW controlled
precharge, the reset values are set to allow a nominal charge voltage range of 4.1 to 10.0V. Upon charger
detection, the charger voltage is compared against the charge voltage limit register values, and charging is
only done if the voltage is within the allowed window. When SW is running the charger detection window
can be re-programmed to comply with product specifications. In Quantum the charge detection window will
be set to comply with Nokia 2mm charging specification for normal and special chargers.
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