User Guide

Mode Description
FLASHING FLASHING mode is for SW downloading.
Voltage limits
Parameter Description Value
VMSTR Master reset threshold (N2200) 2.2V (typ.)
VMSTR+
Threshold for charging, rising
(N2300) 2.1V (typ.)
VMSTR-
Threshold for charging, falling
(N2300) 1.9V (typ.)
VCOFF+ Hardware cutoff (rising) 2.9V (typ.)
VCOFF- Hardware cutoff (falling) 2.6V (typ.)
SWCOFF SW cutoff limit ~3.2V
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.
Power distribution
Power supply components:
• EM ASIC N2200
• EM ASIC N2300
• Application processor VCORE SMPS
• BT
• LDO
• backlight SMPS
• EL-driver
• MicroSD level shifters
• Camera regulators
All the above are powered by the main battery voltage.
Battery voltage is also used on the RF side for power amplifiers (GSM PA & WCDMA PA) and for RF ASIC (N7590,
AHNEUS).
Discrete power supplies are used to generate 2.8V to BT, 1.8 V and 2.8 V for camera HW accelerator and
camera, 1.05V/1.4V for Application processor and 18V for the backlight LEDs.
The device supports both 1.8V/3V SIM cards which are powered by EM ASIC N2200 / VSIM1. Level shifters are
used to power microSD. USB accessories which need power from the device are powered by EM ASIC N2300 /
VOUT.
RM-208
System Module Nokia Customer Care
Issue 1 COMPANY CONFIDENTIAL Page 9 –7
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