AL5802LP

Document number: DS37549 Rev. 4 - 2

8 of 10

www.diodes.com

March 2016

© Diodes Incorporated

AL5802LP

SBR is a registered trademark of Diodes Incorporated

Figure 15 Typical LED Current Response vs. PWM Duty Cycle for

To remove the potential of incorrect connection of the power supply damaging the lamp’s LEDs, many systems use some form of reverse polarity

protection.

series connected diode increases the available voltage to the LED stack and dissipates less power. A circuit example is presented in Figure 16

using Diodes Inc. SBR

®

size of 1mm x 0.6mm, equivalent to an 0402 chip style package. Other reverse voltage ratings are also available on Diodes

Inc.’s website such as

the SBR02U100LP (0.2A/100V) or SBR0220LP (0.2A/20V).

Automotive applications commonly use this method for reverse battery protection.

A second approach, shown in Figure 17, improves upon the method shown in Figure 16. Whereas the method in Figure 16 protects the light

engine, it will not function until the problem has been diagnosed and corrected.

The method shown in Figure 17 not only provides reverse polarity protection, it also corrects the reversed polarity, allowing the light engine to

function.

dissipates less power than standard rectifier bridges.

Figure 16 Application Circuit for LED Driver

with Reverse Polarity Protection

Figure 17 Application Circuit for LED Driver with

Assured Operation Regardless of Polarity

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AL5802LP

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BAS40BRW

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AL5802LP

SDM10U45LP

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