Datasheet

L6924U Operation description
Doc ID 14716 Rev 2 13/37
Figure 6. Typical charge curves in linear mode
The worst case in power dissipation occurs when the device starts the fast-charge phase. In
fact, the battery voltage is at its minimum value. In this case, there is the maximum
difference between the adapter voltage and battery voltage, and the charge current is at its
maximum value.
The power dissipated is given by the following equation:
Equation 1
The higher the adapter voltage is, the higher the power dissipated is. The maximum power
dissipated depends on the thermal impedance of the device mounted on board.
End
Charge
Voltage-Regulation
Phase
Power dissipation
Pre-Charge
Phase
Fast-Charge
Phase
I
PRETH
I
CHG
V
OPRGTH
Battery Voltage
Charge Current
Adapter Voltage
V
ADP
V
PRETH
CHGBATADPDIS
IVVP
×
−
=
)(