The Audio circuit: Earpiece, IHF, internal microphone and external speaker are filtered with discrete
components (common mode reduction coils, Varistors, caps and resistors), where as the external microphone
uses differential mode mic. ASIP
The 16 UEMECLite BB & RF regulators are specified to have a decoupling cap of 1 µF ±20%.
Modes of operation
BB4.0 LiteV2 base band has five different functional modes, which are defined in UEMCLite specification:
• No supply: In NO_SUPPLY mode, the phone has no supply voltage. This mode is due to disconnection of
main battery or low battery voltage level in battery. Phone is exiting from NO_SUPPLY mode when sufficient
battery voltage level is detected. Battery voltage can rise either by connecting a new battery with VBAT >
VMSTR+ or by connecting charger and charging the battery above VMSTR+.
• Acting Dead: If the phone is off when the charger is connected, the phone is powered on but enters a state
called ”Acting Dead”. To the user, the phone acts as if it was switched off. A battery charging alert is given
and/or a battery charging indication on the display is shown to acknowledge the user that the battery is
being charged.
• Active: In the Active mode the phone is in normal operation, scanning for channels, listening to a base
station, transmitting and processing information. There are several sub-states in the active mode
depending on if the phone is in burst reception, burst transmission, if DSP is working etc.
In Active mode the RF regulators are controlled by SW writing into UEMCLite’s registers wanted settings:
VR regulators can be disabled, enabled or forced into low quiescent current mode. VR2 is always enabled
in Active mode for system clock chain supply
• Sleep: In sleep mode VCTCXO is shut down and 32 kHz sleep clock oscillator is used as reference clock for
the base band.
• Charging: Charging can be performed in any operating mode. The battery type / size is indicated by a
resistor inside the battery pack. The resistor value corresponds to a specific battery capacity. This capacity
value is related to the battery technology as different capacity values are achieved by using different
battery technology. The battery voltage, temperature, size and current are measured by the UEMCLite and
controlled by the charging software running in the UPP. The charging control circuitry (CHACON) inside the
UEMCLite controls the charging current delivered from the charger to the battery. The battery voltage rise
is limited by turning the UEMCLite switch off when the battery voltage has reached 4.2 V. Charging current
is monitored by measuring the voltage drop across a 220 mW resistor. The PWM output doesn’t exist any
more from UEMCLite to the bottom connector
Voltage limits
Table 8 Voltage limits
Parameter
Description
Value/V
Vmstr+
Master reset threshold (rising)
2.1 ±0.1
Vmstr-
Master reset threshold (falling)
1.9 ±0.1
Vcoff+
Hardware cutoff (rising)
3.1 ±0.1
Vcoff-
Hardware cutoff (falling)
2.8 ±0.1
SW shutdown
SW cutoff limit (> regulator drop-
out limit) MIN!
3.2 V
Audio function description
The basic audio structure and communication between HW-audio modules and the audio ASIC's is illustrated
in the block diagram below.
RM-298; RM-299
System Module
Page 6 –8
COMPANY CONFIDENTIAL
Issue 1
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