L6924U STMicroelectronics, L6924U Datasheet - Page 29

• 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
9
9.1
9.2
9.3
Additional applications information
Selecting the input capacitor
In most applications, a 1 µF ceramic capacitor, placed close to the V
be used to filter the high frequency noise.
Selecting the output capacitor
Typically, a 4.7 µF ceramic capacitor placed close to the V
keep voltage control loop stable . This ensures proper operation of battery absent detection
in removable battery pack applications.
Layout guidelines and demonstration board
The thermal loop keeps the device at a constant temperature of approximately 120 °C which
in turn, reduces I
ensure a good thermal path. Therefore, the exposed pad must be properly soldered to the
board and connected to the other layer through thermal vias. The recommended copper
thickness of the layers is 70 μm or more.
The exposed pad must be electrically connected to GND.
image of the board with the power dissipation of 1 W. In this instance, the temperature of the
case is 89 °C, but the junction temperature of the device is given by the following equation:
Equation 25
Where the R
and the ambient temperature is 25 °C.
In this case the junction temperature is:
Equation 26
thJA
CHG
of the device mounted on board is 75 °C/W, the power dissipated is 1 W,
. However, in order to maximize the current capability, it is important to
Doc ID 14716 Rev 2
T
T
J
J
=
=
R
75
THJ
×
−
1
A
+
×
25
P
DISS
=
100
+
Additional applications information
T
AMB
o
C
OUT
Figure 22
and V
OUTSN
shows the thermal
IN
and V
pin is enough to
INSN
pins can
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