AAT3687_08 Datasheet, PDF (17/20 Pages) Advanced Analogic Technologies – Lithium-Ion/Polymer Battery Charger

BatteryManager^TM
Output Capacitor
The AAT3687 only requires a 1µF ceramic capacitor on
the BAT pin to maintain circuit stability. This value should
be increased to 10µF or more if the battery connection is
made any distance from the charger output. If the
AAT3687 is to be used in applications where the battery
can be removed from the charger, such as with desktop
charging cradles, an output capacitor greater than 10µF
may be required to prevent the device from cycling on
and off when no battery is present.
PRODUCT DATASHEET
AAT3687
Lithium-Ion/Polymer Battery Charger
Printed Circuit Board
Layout Considerations
For the best results, it is recommended to physically
place the battery pack as close as possible to the
AAT3687 BAT pin. To minimize voltage drops on the PCB,
keep the high current carrying traces adequately wide.
For maximum power dissipation of the AAT3687 3x3mm
TDFN package, the metal substrate should be solder
bonded to the board. It is also recommended to maxi-
mize the substrate contact to the PCB ground plane layer
to further increase local heat dissipation. Refer to the
AAT3687 evaluation board for a good layout example
(see Figures 4 and 5).
AAT3687 Evaluation Board Layout
Figure 4: AAT3687 Evaluation Board
Component Side Layout.
Figure 5: AAT3687 Evaluation Board
Solder Side Layout.
3687.2008.04.1.12
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