21
KX-TG3411BX/KX-TG3412BX/KX-TG3419BX/KX-TGA341BX
4.8.3.
Charge Circuit
Circuit Operation:
When charging the handset on the Base Unit, the charge current is as follows;
DCP+(5.5 V)
→
F301
→
R371
→
R372
→
D362
→
(Base)
→
(Handset)
→
→
Q3
→
F1
→
... Battery...
BATTERY-
→
R45
→
GND
→
CHARGE-(Handset)
→
CHARGE-(Base)
→
GND
→
DCM
In this way, the BBIC on Handset detects the fact that the battery is charged.
The charge current is controlled by switching Q9 of Handset.
4.8.4.
Battery Low/Power Down Detector
Circuit Operation:
“Battery Low” and “Power Down” are detected by BBIC which check the voltage from battery.
The detected voltage is as follows;
• Battery Low
Battery voltage: V(Batt) 2.25 V ± 50 mV
The BBIC detects this level and "
" starts flashing.
• Power Down
Battery voltage: V(Batt) 2.0 V ± 50 mV
The BBIC detects this level and power down.
4.9.
Circuit Operation (Charger Unit)
Charge control is executed at handset side so that the operation when using charger is also controlled by handset.
Refer to
Circuit Operation (Handset)
The route for this is as follows: DC+pin of J1(+)
→
F1
→
R1
→
pad
→
Handset
→
CHARGE-pad
→
DC-pin of J1(-).
Q1
R5
CHG +
Q4
R4
R6
10K
Q9
GND
R7
CHG DET (33)
CHG CTRL (32)
1.2K
CHG -
GND
BATT +
BATTERY
2CELL
BATT +
GND
BBIC
IC1
Q1
R5
Q3
C19
R2
R9
R1
TP1 (pad)
TP2 (CHARGE- pad)
J1
AC Adaptor
F1
(+)
(-)