Absolute maximum ratings
Signal
Min
Nom
Max
Uni
t
Notes
Battery voltage (idle)
-0.3
+4.5
V
Battery voltage maximum value is
specified during charging is active
Battery voltage (Call)
+3.2
+4.3
V
Battery voltage maximum value is
specified during charging is active
Charger input voltage
-0.3
+20
V
Back-Up supply voltage
0
2.5
2.6
V
Maximum capacity of the backup
power supply assumed to be 16 µAh.
Device modes of operation
Mode
Description
NO_SUPPLY
(dead) mode means that the main battery is not present or its voltage is too low (below
EM ASIC D1420 master reset threshold) and that the back-up battery voltage is too low.
BACK_UP
The main battery is not present or its voltage is too low but back-up battery voltage is
adequate and the 32kHz oscillator is running (RTC is on).
PWR_OFF
In this mode (warm), the main battery is present and its voltage is over EM ASIC D1420
master reset threshold.
RESET
RESET mode is a synonym for start-up sequence.
SLEEP
SLEEP mode is entered only from PWR_ON mode with the aid of SW when the system’s
activity is low.
FLASHING
FLASHING mode is for SW downloading.
Voltage limits
Parameter
Description
Value
VMSTR
Master reset threshold (D1420)
2.2V (typ.)
VMSTR+
Threshold for charging, rising (N1310)
2.1V (typ.)
VMSTR-
Threshold for charging, falling (N1310)
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 EM ASICs. If battery voltage is above VMSTR, N1310
charging control logic is alive. Also, RTC is active and supplied from the main battery. Above VMSTR, N1310
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.
RX-34
System Module
Page 9 –6
COMPANY CONFIDENTIAL
Issue 2
Copyright © 2007 Nokia. All rights reserved.
