FAN5616 Datasheet, PDF (12/14 Pages) Fairchild Semiconductor – High-Efficiency, Constant-Current LED Driver with Adaptive Charge Pump

Selecting Capacitors
It is important to select the appropriate capacitor types
and the values for use with the FAN5616. In order to
reduce battery ripple, both C_IN and C_OUT should be low-
ESR capacitors. If necessary, the ripple can be further
reduced by powering the FAN5616 through an RC input
filter, as shown in Figure 9.
PCB Layout Considerations
For best performance, a solid ground plane is recom-
mended on the back side of the PCB. All capacitors
should be placed as close to the FAN5616 as possible
and connected with reasonably thick traces to minimize
the ESL and ESR parasitics.
Input
Power
Supply
0.22Ω
10µF 4.7µF
VIN
FAN5616
GND
Figure 9. Battery Ripple Reduction
Two MLCC bucket capacitors of 0.1µF to 1µF should be
used for best efficiency in boost mode. For better I_LED
regulation, 1µF bucket capacitors are recommended par-
ticularly when I_LED > 25mA and the battery discharges
below 3V.
Figure 10. Recommended PCB Layout
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FAN5616 Rev. 1.0.0
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