LG KB770 Service Manual page 52

3.8.3. Charging control
A programmable charging block in PM6650 is used for battery charging. It is possible to set limits for the
charging current. The external supply typically connects directly to pin (VCHG). The voltage on this pin
(VCHG) is monitored by detection circuitry to ascertain whether a valid external supply is applied or not.
For additional accuracy or to capture variations over time, this voltage is routed internally to the
housekeeping ADC via the analog multiplexer. PM6650 circuits monitor voltages at VCHARGER and
ICHARGE pins to determine which supply should be used and when to switch between the two supplies.
These pins are connected to the Source (or emitter) and Drain (or collector) contacts of the pass transistor
respectively.
4.2V~3.77V
100~70 (%)
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
U8210 Charging Control block
3.76V~3.67V
69~45 (%)
KB770 Battery Bar Display(Stand By Condition)
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3.66V~3.50V 3.50V~3.25
44~20 (%) 19~0 (%)
3. TECHNICAL BRIEF
LGE Internal Use Only