om5448 Hendon Semiconductors, om5448 Datasheet - Page 16

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

9.9
The OM5448 is suitable for providing
a boosted higher voltage power
supply from single or double cell
battery circuits. The most simple
boost power supply circuit is that
shown in figure 18.
2007 May 28, Revision 1.0
Voltage boost power supply
Fig.19 Regulated boost power supply circuit using the OM5448.
Fig.18 Voltage boost power supply circuit using the OM5448.
The circuit is the same as the DC LED
drive circuit of figure 4, except that the
LED has been replaced by a zener
diode. The disadvantage of this circuit
is that if the load current varies over a
wide range, the current carried in the
zener is wasted energy at times of low
load. A regulated supply would be
16
Low Voltage LED Driver
much better if the load on the battery
was only a little more than that
needed by the load. Such a regulating
circuit is shown in figure 19.
These circuits are limited to an output
voltage of a little more than 12 volts,
otherwise the maximum voltage
permitted on pin OP will be exceeded.
and Boost Converter
Product Specification
OM5448