LED Driver PR4404

Various LED applications

Power Flashlight

Components:

LED

current

Vcc

(nominal)

C1a

C1b

L1

D1

Rs

C2a

C2b

150 mA

1.2 – 1.5 V

1 µF

100 µF

6.3 V

1.0 µH

Isat ≥ 1.2 A

MBRS140

1N5817

1.3 Ω

470 nF

22 µF

6.3 V

300 mA

2.4 – 3.0 V

470 nF

100 µF

6.3 V

1.5 µH

Isat ≥ 1.6 A

MBRS140

1N5817

0.67 Ω

470 nF

22 µF

6.3 V

Driving a Chain of LEDs

Output voltages up to 16 V are possible. As the output power of the circuit is limited, the maximum LED

current is lower by a factor roughly equal to the number of LEDs compared with single LED applications.

© PREMA Semiconductor GmbH 2006-2017 I rev. 1017

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