Active Mode; Charging Mode; Power Distribution - Nokia RH-66 Troubleshooting Manual

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Sleep mode is exited either by the expiration of a sleep clock counter in the UEMC or by
some external interrupt (generated by a charger connection, key press, headset
connection, etc.). The VCTCXO is shut down in sleep mode and the 32 kHz sleep clock
oscillator is used as a reference clock for the baseband.

Active Mode

In active mode, the mobile terminal operates normally by scanning for channels,
listening to a base station, and transmitting and processing information. There are
several sub-states in the active mode depending on the mobile terminal present state of
the mobile terminal, such as burst reception, burst transmission etc.
In active mode, software controls the UEMC RF regulators: VR1A and VR1B can be
enabled or disabled. VSIM can be enabled or disabled and its output voltage can be
programmed to be 1.8 V or 3.3 V. VR2 and VR4—VR7 can be enabled or disabled or forced
into low quiescent current mode. VR3 is always enabled in active mode and disabled
during sleep mode and cannot be controlled by software in the same way as the other
regulators. VR3 only turns off if both processors request to be in sleep mode.

Charging Mode

Charging mode can function in parallel with any other operating mode. A BSI resistor
inside the battery pack indicates the battery type/size. The resistor value corresponds to
a specific battery capacity. The UEMC measures the battery voltage, temperature, size,
and charging current.
CHACON inside the UEMC controls the charging current delivered from the charger to
the battery and mobile terminal. The battery voltage rise is limited by turning the UEMC
switch off when the battery voltage has reached 4.2 V. The charging current is monitored
by measuring the voltage drop across a 220 mOhm resistor.

Power Distribution

In normal operation, the baseband is powered from the mobile terminal's battery. The
battery consists of one lithium-ion cell capacity of 1070 mAh and some safety and
protection circuits.
The UEMC ASIC controls the power distribution to the whole mobile terminal through
the baseband and RF regulators excluding the power amplifier (PA), which has a
continuous power rail directly from the battery. The battery feeds power directly to the
following parts of the system:
• UEMC
• PA
• Vibra
• Display
• Keyboard lights
Issue 1 03/2005
©2005 Nokia Corporation
2115i/2116/2116i (RH-66)
Baseband Description and Troubleshooting
Company Confidential Page 11