FAN5607 Fairchild Semiconductor, FAN5607 Datasheet - Page 11

• Manufacturer Part Number: FAN5607
• Description: LED Driver with Adaptive Charge Pump DC/DC Converter
• Manufacturer: Fairchild Semiconductor

PRODUCT SPECIFICATION
Selecting Capacitors
It is important to select the appropriate capacitor types and
the values for use with the FAN5607. These capacitors deter-
mine parameters such as power efficiency, maximum sus-
tainable load current by the charge pump, input and output
ripple and start-up process.
In order to reduce ripple, both C
ESR capacitors. Increasing the C
output ripple voltage. However this will increase the power-
on time. The C
this ripple can be further reduced by powering the FAN5607
REV. 1.0.0 6/22/04
Power
Supply
Input
Figure 7. Battery Ripple Reduction
IN
value controls input ripple. If necessary,
10µF
0.22Ω
IN
4.7µF
OUT
and C
capacitor reduces the
OUT
V
GND
FAN5607
IN
should be low
through the RC input filter, as shown in Figure 7. Two low
ESR bucket capacitors of value between 0.1µF to 1µF,
should be used for best efficiency in boost mode. The bucket
capacitor, CAP1 = CAP2 = 1µF is recommended, if the
FAN5607 is required to start at battery voltage lower than
3V.
PC Board Layout
For best performance, a solid ground plane is recommended
on the back side of the PCB. The ground tails of C
C
IC.
OUT
should be connected together close to the GND pin of
FAN5607
IN
and
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