The BCR420U/BCR421U provide a low-cost solution for driving 0.25W LEDs with a typical LED current ILED of 75mA to 150mA. Internal breakdown voltage is >40V, this is the maximum voltage that the LED driver IC can sustain when connected to it directly. The BCR420U/BCR421U can be operated at supply voltages of 40V or higher, by simply stacking a series of LEDs in front of the LED drivers, resulting in a certain voltage drop depending on the forward voltages of the LEDs, reducing the voltage at the supply pin of the driver below 40V. A digital input pin (BCR421U) allows dimming via a Microcontroller with frequencies of up to 10 kHz. A reduction of the output current at higher temperatures is the result of the negative thermal coefficient of 0.2% /K. of the LED drivers. With no need for additional external components like inductors, capacitors and free wheeling diodes, the BCR420U/BCR421U LED drivers are a cost-efficient and PCB-area saving solution for driving 0.25W LEDs.