om5448 Hendon Semiconductors, om5448 Datasheet - Page 12

• Manufacturer Part Number: om5448
• Description: Low Voltage Led Driver And Boost Converter
• Manufacturer: Hendon Semiconductors

In figure 12 4.7 ohm resistors have
been used in series with each of the
three parallel LEDs to force current
sharing. At 20 mA the voltage drop
across the resistors will be
approximately 100 mV.
2007 May 28, Revision 1.0
Fig.12 Parallel LED drive using the OM5448 (with current sharing resistors).
Fig.13 Series LED drive using the OM5448
Series LED connection is shown in
figure 13. Three series LEDs have
been shown, although a larger
number can be driven up to the
maximum voltage allowed on V
(14 V).
12
OP
Low Voltage LED Driver
As the output voltage increases, the
output drive part of each cycle
becomes shorter, and the output drive
duty cycle falls. This needs higher
peak currents in the inductor to
maintain a sufficient average LED
load current.
and Boost Converter
Product Specification
OM5448