Power Key - Nokia N72 Service Manual

RM-180
System Module
Voltage limits
Parameter Description
Master reset
threshold
VMSTR (N2200)
Threshold
for
charging,
rising
VMSTR+ (N2300)
Threshold
for
charging,
falling
VMSTR- (N2300)
Hardware
cutoff
VCOFF+ (rising)
Hardware
cutoff
VCOFF- (falling)
SW cutoff
SWCOFF limit
The master reset threshold controls the internal reset of N2200 / (N2300). If battery voltage is above VMSTR,
N2300's charging control logic is alive. Also, RTC is active and supplied from the main battery. Above VMSTR,
N2300 allows the system to be powered on although this may not succeed due to voltage drops during start
up. SW can also consider battery voltage too low for operation and power down the system.

Power key

The system boots up when power key is pressed (adequate battery voltage, VBAT, present).
Power down can be initiated by pressing the power key again (the system is powered down with the aid of
SW). Power on key is connected to N2200 ASIC via PWRONX signal.
Issue 1
Value
2.2V (typ.)
2.1V (typ.)
1.9V (typ.)
2.9V (typ.)
2.6V (typ.)
~3.2V
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