Nokia NHM-7 series, Service Manual, Page: 33 / 212

NHM–7
System Module & UI
PAMS Technical Documentation
Page 21
Issue 1 10/2001
Nokia Corporation
2.78V or 3.3V. VR4 –VR7 can be enabled or disabled or forced into low
quiescent current mode. VR3 is always enabled in active mode.
Sleep mode
Sleep mode is entered when both MCU and DSP are in stand–by mode.
Sleep is controlled by both processors. When SLEEPX low signal is de-
tected UEM enters SLEEP mode. VCORE, VIO and VFLASH1 regulators
are put into low quiescent current mode. All RF regulators are disabled in
SLEEP. When SLEEPX=1 is detected UEM enters ACTIVE mode and all
functions are activated.
The sleep mode is exited either by the expiration of a sleep clock counter
in the UEM or by some external interrupt, generated by a charger con-
nection, key press, headset connection etc.
In sleep mode VCTCXO is shut down and 32 kHz sleep clock oscillator is
used as reference clock for the baseband.
Charging
The battery voltage, temperature, size and current are measured by the
UEM controlled by the charging software running in the UPP.
The charging control circuitry (CHACON) inside the UEM controls the
charging current delivered from the charger to the battery. The battery
voltage rise is limited by turning the UEM switch off when the battery volt-
age has reached 4.2 V. Charging current is monitored by measuring the
voltage drop across a 220 mOhm resistor.
Supply Voltage Regulation
Supply voltage regulation is controlled by UEM asic. There are six sepa-
rate regulators used by baseband block.
BB Regulators
Signal Min Nom Max Note
VANA 2.70V 2.78V 2.86V I
max
= 80mA
VFLASH1 2.70V 2.78V 2.86V I
max
= 70mA
I
Sleep
= 1.5mA
VFLASH2 2.70V 2.78V 2.86V I
max
= 40mA
VSIM 1.745V
2.91V
1.8V
3.0V
1.855V
3.09V
I
max
= 25mA
I
Sleep
= 0.5mA
VIO 1.72V 1.8V 1.88V I
max
= 150mA
I
Sleep
= 0.5mA
VCORE 1.0V
1.235V
1.425V
1.710V 1.053V
1.3V
1.5V
1.8V 1.106V
1.365V
1.575V
1.890V I
max
= 200mA
I
Sleep
= 0.2mA
Default value =
1.5V