Diodes Incorporated's AL8843 is a hysteretic mode DC-DC step-down converter, designed for driving single or multiple series connected LEDs efficiently from a voltage source higher than the LED voltage. The device can operate from an input supply between 4.5 V and 40 V and provide an externally adjustable output current up to 3 A. The AL8843 integrates the power switch and a high-side output current sensing circuit, which uses an external resistor to set the nominal average output current. Dimming can be realized by applying an external control signal to the CTRL pin. The CTRL pin will accept either a DC voltage signal or a PWM signal. AL8843 is available in the thermally enhanced a SO-8EP package.