AL5802LP4

Document number: DS37441 Rev. 4 - 2

8 of 10

www.diodes.com

February 2016

© Diodes Incorporated

AL5802LP4

PWM dimming can be achieved by driving the EN Pin. An external open-collector NPN transistor or open-drain N-Channel MOSFET can be used

to drive the EN Pin as shown in Figure 14. Dimming is achieved by turning the LEDs ON and OFF for a portion of a single cycle. The PWM signal

can be provided by a micro-controller or analog circuitry. Figure 16 is a typical response of LED current vs. PWM duty cycle on the EN Pin.

-or-

Figure 14 Application Circuits for LED Driver with PWM Dimming Functionality

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.

increases the available voltage to the LED stack and dissipates less power. A circuit example is presented in Figure 16 using Diodes Inc

orporated’s

0.6mm, equivalent to an 0402 chip style package. Other reverse voltage ratings are available on

Diodes’ website, such as the SBR02U100LP

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

Automotive applications commonly use this method for reverse battery protection.

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