Diodes AL9901 buck LED driver creates a constant LED current programmed by one external resistor. It offers a switching frequency up to 300 kHz determined by an external single resistor. The LED brightness can be varied by both linear and PWM dimming using the AL9901’s LD and PWM pins respectively. The PWM input operates with duty ratio of 0 to 100% and frequency of up to several kHz. The AL9901 is available in the SO-16 and also the thermally enhanced DFN6040-12 packages.