Power Distribution - Nokia 7088 Troubleshooting Manual

7088 (Flower)
Base band Description and Troubleshooting
temperature, size, and charging current.
The charger control block situated inside the PM controls the charging current
delivered from the charger to the battery and mobile terminal. The maximum battery
voltage is limited by turning the PM switch off when the battery voltage reaches 4.2 V.
The charging current is monitored by measuring the voltage drop across a 0.1 ohm
resistor.

Power Distribution

In normal operation, the base band is powered by the mobile terminal's battery pack.
The battery pack consists of one lithium-ion cell with a capacity of 700 mAh and
safety and protection circuits.
The PM6610 IC controls the power distribution to the whole mobile terminal, which
includes the base band and the RF regulators, but excludes the RF power amplifier
(RF PA). RF power amplifier drains power from the battery directly. The battery
provides power directly to the following parts of the system:
PM6610
RF PA
Vibrator
Keyboard & LCD backlights
Audio Amplifier
Flash light
Regulator for camera
The heart of the power distribution is the power control block inside the PM6610. It
includes all the voltage regulators and feeds the power to the entire system. The
PM6610 handles hardware power-up functions so that the regulators are not
powered on and the power-up reset (PURX) is not released if the battery voltage is
less than 3 V.
The following PM6610 regulators power the base band:
Page 10 © 2006 Nokia Corporation Company Confidential Issue 1 12/2006