
www.austriamicrosystems.com
Revision 1.10
39 - 86
AS3542 3v2
Data Sheet, Strictly Confidential - D e ta i l e d D e s c r i p t i o n - P o w e r M a n a g e m e n t F u n c t i o n s
Figure 28. Charger States
9.4.2 Soft
Charge
If the battery and therefore CHGOUT is below 3V the charger is working in a fixed soft charge mode with the smallest
possible charging current of 55mA and 3.9V charger end voltage. After reaching the 3V level the charger switches to
the register defined mode and sets the programmed charging current and voltage.
9.4.3 End of Charge Detection
For the EOC level 4 presets can be selected. This makes it possible to monitor the charging progress also during con-
stant voltage mode. If the EOC level is reached an interrupt can be generated, but it is also possible to poll the charger
status bits at any time.
9.4.4 Temperature
Supervision
This charger block also features a 15uA supply for an external 100k NTC resistor to measure the battery temperature
while charging. If the temperature is too high, an interrupt can be generated. If the battery temperature drops the char-
ger will start charging again. The levels for switching off/on the charger (45/42°C or 55/50°C) can be selected via reg-
ister settings.
If the NTC resistor does not have 100k
Ω
its value can be corrected with a resistor in series or in parallel.
9.4.5 Parameter
AVDD27=2.7, T
A
= 25
o
C, unless otherwise mentioned
Table 25. Charger Parameter
Symbol
Parameter
Condition
Min
Typ
Max
Unit
I
CHG
(0-7)
Charging Current
BVDD > 2.7V, I
CHG
> 70mA
I
NOM
-8%
I
NOM
I
NOM
+8%
mA
V
CHG
(0-7)
Charging Voltage
BVDD > 2.7V, end of charge is
true
V
NOM
-50mV
V
NOM
V
NOM
+30mV
V
V
ON_ABS
Charger On Voltage IRQ
CHGOUT>3V
3.1
4.0
V
V
ON_REL
Charger On Voltage IRQ
CHGIN-CHGOUT
170
240
mV
V
OFF_REL
Charger Off Voltage IRQ
CHGIN-CHGOUT
40
77
mV