AP8802

1A LED Step-Down Converter

AP8802 Rev. 1

6 of 13

MARCH 2009

www.diodes.com

Inductor Selection

This section highlights how to select the inductor suitable for the application requirements, in terms of

switching frequency, LED current accuracy and temperature.

Switching Frequency @ILED = 700mA

47

68

100

150

220

470

47

68

100

150

220

470

68

100

150

220

470

0

50

100

150

200

250

300

350

400

450

500

0

50

100

150

200

250

300

350

400

450

500

Inductor Value [uH]

12V - 3 LEDs

24V - 5 LEDs

48V - 10 LEDs

Figure 4: Switching Frequency Vs Inductor Value

The inductor influences the LED current accuracy that the system is able to provide. The following section

highlights how to select the inductor in relation to the device packages and the LED current, while maintaining

the chip temperature below 70˚C.