L6924UTR datasheet(13/37 Pages) STMICROELECTRONICS

Part #	L6924UTR

Description	USB compatible battery charger system with integrated power switch for Li-Ion/Li-Polymer

PDF	37 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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13 / 37 page

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

PRETH

CHG

OPRGTH

Battery Voltage

Charge Current

Adapter Voltage

ADP

PRETH

CHG

BAT

ADP

DIS

−

)

(

L6924UTR Datasheet(PDF) 13 Page - STMicroelectronics