L6924U STMicroelectronics, L6924U Datasheet - Page 13

• Manufacturer Part Number: L6924U
• Description: Battery Management USB Battery Charger System w/integra
• Manufacturer: STMicroelectronics

Specifications of L6924U

• Product: Charge Management
• Battery Type: Li-Ion
• Output Voltage: 4.2 V
• Output Current: 30 mA
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Package / Case: VFQFPN
• Mounting Style: SMD/SMT
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

L6924U
Figure 6.
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.
V
V
OPRGTH
I
PRETH
V
PRETH
I
CHG
ADP
Typical charge curves in linear mode
Pre-Charge
Phase
Adapter Voltage
Doc ID 14716 Rev 2
Fast-Charge
P
DIS
Phase
=
(
V
ADP
−
V
BAT
)
×
Voltage-Regulation
I
CHG
Power dissipation
Battery Voltage
Charge Current
Phase
Operation description
Charge
End
13/37