FAN5608_06 FAIRCHILD [Fairchild Semiconductor], FAN5608_06 Datasheet - Page 8

• Manufacturer Part Number: FAN5608_06
• Description: Serial / Parallel LED Driver with Current-Regulated, Step-Up DC/DC Converter
• Manufacturer: FAIRCHILD [Fairchild Semiconductor]

© 2006 Fairchild Semiconductor Corporation
FAN5608 Rev. 1.0.5 • 8/8/06
Typical Characteristics
T
Design and Component Selection Guidelines
Inductor Selection
The inductor is one of the main components required by
the boost converter to store energy. The amount of
energy stored in the inductor and transferred to the load
is controlled by the regulator, using pulse-frequency
modulation (PFM) and pulse-skipping techniques. In most
cases, the FAN5608 operates in discontinuous conduction
mode, resulting in higher inductor current ripple.
To ensure proper operation of the current regulator over
the entire range of conditions, select the inductor based
A
=25C, V
BAT
Figure 11. Peak power efficiency
Figure 13. Startup Response
= 3.6V, unless otherwise specified.
Startup Response
V
IN
=3.6V, L=6.8uH, C
Tim e 200µS/Div
OUT
=4.7uF, 3-LEDs/CH
8
on the maximum output power (P
input voltage (V
where units of L, V
respectively and T = 0.4μs is a factor depending upon
the
relationship is applicable up to P
L
L
≤
≥
(
2
V
2 .
FAN5608
IN
P
μ
OUT
)
H
2
×
. At lower inductor values, the efficiency
T
Figure 12. PWM Dimming
IN
):
internal
IN
, and P
OUT
architecture.
are in μH, Volt, and Watt,
OUT
) and the minimum
OUT
= 0.8W and
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The
EQ 6
above