Usb Charging Circuit - LG Prada KE850 Service Manual

3. TECHNICAL BRIEF

3.15. USB charging circuit

The USB charging circuit is a fully integrated USB VBUS voltage single-cell Li-ion battery charger
circuit. The charger uses a CC/CV charge profile required by Li-ion batteries. CC charging current and
End of charging current is programmable I
I resistor between this pin and the GND pin to set the charge current limit determined by the
REF
following equation:
I = 12089/30K = 400mA
CC
The End Of Charging current is set by I
I = 11000/110K = 100mA
EOC
& I
REF
That can be programmed by the as following equation:
MIN
USB CHARGING
2V72_IO
R118
100K
USB_VBUS
TP105
USB_EOC
USB_CHG_EN
C128
1u
Figure 25 USB charging circuit
resistors.
MIN
VBAT
U106 ISL6294
1 8
VIN BAT
2 7
_PPR IREF
3 6
_CHG IMIN
4 5
_EN GND
9
PGND
R125 R126
C129
1u
110K 30K
(1%)
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