Power Up; Power Up With A Charger; Power Up With The Power Switch (Pwronx) - Nokia NSB-5 Series Technical Documentation Manual

NSB-5
System Module
VSIM and V5V can give a total of 30 mA.

Power Up

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 con-nected 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 a charger

When the charger is connected, CCONT will switch on the CCONT digital voltage as soon
as the battery voltage exeeds 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
diagram assumes empty battery, but the situation would be the same with full battery:
When the phone is powered up with an empty battery pack using the standard charger,
the charger may not supply enough current for standard power-up procedure and the
powerup must be delayed.

Power Up With the Power Switch (PWRONX)

When the power on switch is pressed the PWRONX signal will go low. CCONT will switch
on the CCONT digital section and VCXO as was the case with the charger-driven power
up. If PWRONX is low when the 64 ms delay expires, PURX is released and SLEEPX control
goes to MAD. If PWRONX is not low when 64 ms expires, PURX will not be released, and
CCONT will go to power off ( digital section will send power off signal to analog parts)
Page 22
Nokia Mobile Phones Ltd.
PAMS Technical Documentation
Issue 1 03/01
.