Diodes' BCR420U and BCR421U constant-current regulators provide a simple means of driving low-power LED strings. Target applications are those that benefit from the improved efficiency, flexibility, and longer life offered by LEDs as an emerging lighting source.

Supporting adjustable currents from 10 mA to 350 mA allows for platform designs based on a single device to be used across multiple LED strip applications, considerably easing a manufacturer’s overall qualification process. These LED drivers also enhance system reliability as the monolithic integration of transistors, diodes, and resistors both simplify system design and reduce component count.

The 40 V maximum input rating ensures sufficient headroom for transient supply voltages and allows for LED short failures on long strings. With its low-side driver configuration, the BCR421U has the added feature of an enable function that can adjust the light output level using a PWM input signal.