AN4501 datasheet(24/48 Pages) STMICROELECTRONICS

Part #	AN4501

Description	Design of a boost LED driver using L99LD01

PDF	48 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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24 / 48 page

Selection of the inductor

AN4501

24/48

DocID026394 Rev 1

4.8

Inductor RMS current

The inductor RMS current (IL,RMS) is needed to calculate the inductor copper loss (power

dissipation caused by resistance of the inductor wires, noted DCR).

The waveform of the inductor current in CCM is a triangular signal with an average current

of IL and a peak-to-peak current IL,PP (see Figure 4).

IL,RMS is given by (see Section 8.7 for the details of the calculations):

Equation 16:

Similarly to IL,PEAK, IL,RMS is also in general reached at DMAX (and VIN,MIN)

The maximum copper loss is PCOPPER,MAX = DCR x I

L,RMS,MAX

LR MS

LPP

-----------------

L R MS MAX

LM AX

LPP V

INMIN

()

--------------------------------------

OU T

MAX

–

()

---------------------------------

LPP V

INMIN

()

--------------------------------------

AN4501 Datasheet(PDF) 24 Page - STMicroelectronics