AP5726

WHITE LED STEP-UP CONVERTER

AP5726 Rev. 1

9 of 16

JUNE 2009

www.diodes.com

Inductor Selection

efficiency are major concerns, the inductor should have low core losses at 1.2MHz and low DCR (copper wire

resistance).

Capacitor Selection

The small size of ceramic capacitors are ideal for AP5726 applications. X5R and X7R types are

recommended because they retain their capacitance over wider voltage and temperature ranges than other

applications.

Diode Selection

Schottky diodes, with their low forward voltage drop and fast reverse recovery, are the ideal choices for

AP5726 applications. The forward voltage drop of a Schottky diode represents the conduction losses in the

For diode selection, both

forward voltage drop and diode capacitance need to be considered.

Schottky diodes with higher current

ratings usually have lower forward voltage drop and larger diode capacitance, which can cause significant

switching losses at the 1.2MHz switching frequency of the AP5726. A Schottky diode rated at 100mA to

200mA is sufficient for most AP5726 applications.

LED Current Control

5

62

10

31

15

20.6

20

15.5

30

10.3

Application Information