Absolute Maximum Ratings; Device Modes Of Operation - Nokia RX-44 Service Manual

Absolute maximum ratings

Signal
Battery voltage (idle)
Battery voltage (Call)
Charger input voltage
Back-Up supply voltage

Device modes of operation

Mode
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
VMSTR Master reset threshold (D1420)
VMSTR+ Threshold for charging, rising (N1310)
VMSTR- Threshold for charging, falling (N1310)
VCOFF+ Hardware cutoff (rising)
VCOFF- Hardware cutoff (falling)
SWCOFF SW cutoff limit
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.
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Min Nom
-0.3
+3.2
-0.3
0 2.5
Description
COMPANY CONFIDENTIAL
Copyright © 2007 Nokia. All rights reserved.
Uni
Max
t
+4.5 V Battery voltage maximum value is
specified during charging is active
+4.3 V Battery voltage maximum value is
specified during charging is active
+20 V
2.6 V Maximum capacity of the backup
power supply assumed to be 16 µAh.
Description
2.2V (typ.)
2.1V (typ.)
1.9V (typ.)
2.9V (typ.)
2.6V (typ.)
~3.2V
RX-44
System Module
Notes
Value
Issue 1