LED6000 datasheet(36/49 Pages) STMICROELECTRONICS

Part #	LED6000

Description	3 A, 61 V monolithic current source with dimming capability

PDF	49 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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36 / 49 page

Application notes - alternative topologies

LED6000

36/49

DocID027777 Rev 2

The peak current flowing in the embedded switch is:

Equation 29

While its average current level is equal to:

Equation 30

This is due to the fact that the current flowing through the internal power switch is delivered

to the output only during the OFF phase.

The switch peak current must be lower than the minimum current limit of the overcurrent

protection and the average current must be lower than the rated DC current of the device.

In addition to these constraints, the thermal considerations summarized in Section 5.4 on

page 30 must also be evaluated.

Figure 23. Inverting buck-boost schematic

Figure 23 shows the schematic circuit for an LED current source based on inverting buck-

boost topology. The input voltage ranges from 15 to 30 V and it can drive a string composed

of 8 LEDs with 0.5 A DC.

OUT

RIPPLE

OUT















OUT





LED6000 Datasheet(PDF) 36 Page - STMicroelectronics