Linear LED controllers boast efficiency and accuracy

By Alix Paultre, contributing editor

Diodes Incorporated’s AL5814, AL5817, AL5815, and AL5816 linear LED controllers deliver dimmable and adjustable drive current for LED strings with more than 80% efficiency. Accepting an input from 4.5 V to 60 V, the inductor-free devices maintain good EMI performance, making system integration simpler, and internal power dissipation is also minimized due to an external power transistor.

The AL58xx series can provide up to 15 mA to an external MOSFET or bipolar transistor to drive LED strings, and the drive current is configured by an external resistor with 4% reference voltage accuracy. Delivering excellent temperature stability, the AL5815 and AL5816 devices support PWM dimming, while the AL5814 and AL5817 devices support both analog and PWM dimming.

Protection features include overtemperature and input undervoltage lock-out. The AL5814 and AL5817 devices also provide “LED open” protection via a VFAULT pin, as well as LED thermal fold-back protection. The AL58xx series is available in SOT-25 and thermally enhanced MSOP-8EP packages. The AL5815 and AL5816 are priced at $0.15 each in 10K quantities, while the AL5814 and AL5817 are priced at $0.20 in 10K quantities.