Specifications

WM_PRJ_Q2400_PTS_001 - 003
6th November 2002
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2.12 Battery charging interface
The WISMO Quik Q2403 Series module supports one battery charging circuit
for Li-Ion batteries. This circuit uses an interface which consists of a current
source inputs (CHG_IN) where the constant current has to flow in order to
charge the battery. This current value depends on the battery capacity. It is
recommended to provide a current equal to the value of the capacity plus
50mA. For a 550mA battery the current will be 600mA. The maximum current
is 800mA.
A specific AT command (+WCBM), available from 4.3 level, allows to manage
the charge battery (start and stop the charge, enable or disable unsolicited
Battery Charge Indications and set the battery charge parameters).
The WISMO Quik Q2403 Series module monitors the battery voltage to detect
the end of the charge. WISMO Quik Q2403 Series also monitors the
temperature of the battery through the BAT_TEMP pin which has to be
connected to a temperature sensor inside the battery (a NTC resistor for
instance).
Pin description
Signal Pin number I/O I/O type Description
CHG_IN 1, 2, 4 I Analog Current source
input
BAT_TEMP 38 I Analog A/D converter
Electrical Characteristics
Parameter Min Max Typ Unit
BAT_TEMP resolution 10 bits
BAT_TEMP sampling rate 90.3 Ksps/s
BAT_TEMP Input Impedance ( R ) 4.7
k
Ω
BAT_TEMP Input Impedance ( C ) 100 nF
CHG_IN Voltage (for I=Imax) +VBATT max +
0.7V
TBD* V
CHG_IN Current 800 mA
BAT_TEMP Input signal range 2.8 V
* To be parametrized as per battery manufacturer