Power Up And Power Down; Power Up With Charger - Nokia NSB-7 Series Service Manual

NSB-7
System Module
In the next figure the principle of the SMR / VSIM-functions is shown.
VBAT

Power Up and Power Down

The baseband is powered up by:
1 Pressing the power key, that generates a PWRONX interrupt signal from the
power key to the CCONT, which starts the power up procedure.
2 Connecting a charger to the phone. The CCONT recognizes the charger from the
VCHAR voltage and starts the power up procedure.
3 A RTC interrupt. If the real time clock is set to alarm and the phone is switched
off, the RTC generates an interrupt signal, when the alarm is gone off. The RTC interrupt
signal is connected to the PWRONX line to give a power on signal to the CCONT just like
the power key.
4 A battery interrupt. Intelligent battery packs have a possibility to power up the
phone. When the battery gives a short (10ms) voltage pulse through the BTEMP pin, the
CCONT wakes up and starts the power on procedure.

Power up with charger

When the charger is connected CCONT will switch on the CCONT digital voltage as soon
as the battery voltage exceeds 3.0V. The reset for CCONT's digital parts is released when
the operating voltage is stabilized (50 us from switching on the voltages). Operating
voltage for VCXO is also switched on. The counter in CCONT digital section will keep
MAD in reset for 62 ms (PURX) to make sure that the clock provided by VCXO is stable.
After this delay MAD reset is released, and VCXO -control (SLEEPX) is given to MAD. The
next diagram explains the power on procedure with charger (the picture assumes empty
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CCONT
V5V_4
V5V_3
V5V_2
VSIM 5V reg
V5V
Figure 9: Principle of the SMR Power Functions
ãNokia Mobile Phones Ltd.
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